My brakes are driving me nuts..

PANDDDKP · 06-11-2016 5:59pm #1

My brakes were perfect except for when i was coming to a stop. If I applied the brakes while driving just to slow down they were perfect.

But when the van was just about to stop and I had my foot still on the pedal, at the last second they make 2 or 3 banging noises and at the same time the pedal would vibrate.

So I sent it off to the mechanic, got it back yesterday, he replaced all 4 pads, and 2 front discs saying they needed doing. Fair enough I said.

But when I drove it yesterday, they pedal is really spongey, and the banging is still there when I stop, along with the pedal vibrating. Basically they're worse than ever. I told him and he started bleeding them, then he said the master brake cylinder needed doing now because the pedal is going to the floor, it never went to the floor before..

I'm pissed off now... Anyone have any idea whay the pedal is spongey, and what the banging is? He said he wasn't sure what the banging is, but it could be the pump....

martinr5232 · 06-11-2016 6:41pm

The banging and pullsing is your abs kicking in.
What are your tyres like ??
The spongey peddle may just be the new pads needing bedding in i wouldnt be going bleeding brakes if i didnt open any pipes.

porsche boy · 06-11-2016 7:05pm

Did you describe your problem to him or just ask for new pads & discs?
Either way the vibration in the pedal is your ABS kicking in. What car/year/mileage is it?

PANDDDKP · 06-11-2016 7:21pm

martinr5232 wrote: »

The banging and pullsing is your abs kicking in.
What are your tyres like ??
The spongey peddle may just be the new pads needing bedding in i wouldnt be going bleeding brakes if i didnt open any pipes.

Front tyres are new ish. Put them on in July. Rear tyres are nearly 2 years old but the thread on them looks good. I've had pads changed before on the van and never had a spongey pedal.

PANDDDKP · 06-11-2016 7:25pm

porsche boy wrote: »

Did you describe your problem to him or just ask for new pads & discs?
Either way the vibration in the pedal is your ABS kicking in. What car/year/mileage is it?

I described it to him, but I was out of the country, so when he looked at the discs they were warped and pads needed changing he said. The vibration and noise has been happening for about 2 months, it happened the same day I asked a different mechanic to look at the brakes, (van was in for coolant issue) and that mechanic said all brakes were fine, but as I was driving home that day the noise appeared as I was coming to a stop.

I took it for a drive a min ago on a quiet road and slammed on the brakes a few times, the van will not skid! It's a 2009 Combo van.

Hal1 · 06-11-2016 8:12pm

Well if brakes feel spongy there's air in the system. I'd be checking the abs sensors are working correctly too.

PANDDDKP · 06-11-2016 8:15pm

Hal1 wrote: »

Well if brakes feel spongy there's air in the system. I'd be checking the abs sensors are working correctly too.

I drove the van yesterday and the mechanic had his OBD2 scanner hooked up to the van for the drive, no faults came up for the abs.

CianRyan · 06-11-2016 8:31pm

Spongy pedal is almost definitely (almost because I haven't felt it) air in the line or old, bad fluid.

PANDDDKP · 06-11-2016 8:37pm

CianRyan wrote: »

Spongy pedal is almost definitely (almost because I haven't felt it) air in the line or old, bad fluid.

He said he put new fluid in it. The old fluid was too thick he said, so he put the recommended lighter oil in the brake fluid reservoir. He said the thicker oil could ruin the master cylinder and abs.

CianRyan · 06-11-2016 8:45pm

PANDDDKP wrote: »

He said he put new fluid in it. The old fluid was too thick he said, so he put the recommended lighter oil in the brake fluid reservoir. He said the thicker oil could ruin the master cylinder and abs.

The fluid on a 7 year old van is never going to be that bad, sounds like he lied to you.
Brake fluid is measured in how much moisture it's taken in, the more water in it the less effective it is. If your brakes are going to the floor and you have no power, he may have started to bleed the brakes, let the resivour go dry and taken a lot of air into the system.
It's an easy fix, just pump each brake with the nipple opening and closing until there's no more air coming out, keeping the fluid level correct. Perhaps he just wasn't arsed when he realised he ****ed up? God knows.

Go back to him and ask him to do the job properly or show you where the fluid is leaking from the master cylinder.

PANDDDKP · 06-11-2016 9:10pm

CianRyan wrote: »

The fluid on a 7 year old van is never going to be that bad, sounds like he lied to you.
Brake fluid is measured in how much moisture it's taken in, the more water in it the less effective it is. If your brakes are going to the floor and you have no power, he may have started to bleed the brakes, let the resivour go dry and taken a lot of air into the system.
It's an easy fix, just pump each brake with the nipple opening and closing until there's no more air coming out, keeping the fluid level correct. Perhaps he just wasn't arsed when he realised he ****ed up? God knows.

Go back to him and ask him to do the job properly or show you where the fluid is leaking from the master cylinder.

He said an easy fix (but not recommended) was just to put a heavier brake fluid back into it but he said it could damage the master cylinder and abs. So I dunno what to do...

CianRyan · 06-11-2016 9:27pm

PANDDDKP wrote: »

He said an easy fix (but not recommended) was just to put a heavier brake fluid back into it but he said it could damage the master cylinder and abs. So I dunno what to do...

I'd be dubious of anything he tells you to be honest, I'd take the van elsewhere for a second option.

tossy · 06-11-2016 9:35pm

The ABS kicking in just as your about to stop is the ABS speed sensor - it might be faulty or just need to be adjusted slightly. - had it on an A4 the sensor just needed to be re sat into the hub properly. It won't show any code or fault in the ECU.

Different mechanic time.

jimbis · 06-11-2016 10:24pm

A lot of crap building up on the abs sensors can also cause issues. Anytime I change brakes I always blow the crap off the sensor with an air hose.

_Brian · 06-11-2016 10:53pm

I'd be thinking of a fluid change.

The fluid down near the wheel just gets shoved in/out of the salve cylinder and heated repeatedly, it looses its properties and needs draining off.

Most cars call for fluid changes every two years.

Del2005 · 06-11-2016 11:36pm

PANDDDKP wrote: »

Front tyres are new ish. Put them on in July. Rear tyres are nearly 2 years old but the thread on them looks good. I've had pads changed before on the van and never had a spongey pedal.

PANDDDKP wrote: »

I described it to him, but I was out of the country, so when he looked at the discs they were warped and pads needed changing he said. The vibration and noise has been happening for about 2 months, it happened the same day I asked a different mechanic to look at the brakes, (van was in for coolant issue) and that mechanic said all brakes were fine, but as I was driving home that day the noise appeared as I was coming to a stop.

I took it for a drive a min ago on a quiet road and slammed on the brakes a few times, the van will not skid! It's a 2009 Combo van.

How close to the new tyres did you notice the noise and vibrations? What brand are the tyres?

BorneTobyWilde · 06-11-2016 11:55pm

Could be steering bushes.
Sounds like air in system. Go back tell him to bleed it again and check all steering joints.

PANDDDKP · 07-11-2016 9:51am

_Brian wrote: »

I'd be thinking of a fluid change.

The fluid down near the wheel just gets shoved in/out of the salve cylinder and heated repeatedly, it looses its properties and needs draining off.

Most cars call for fluid changes every two years.

He changed the fluid when he did the brakes so I'm assuming that'd be new fluid?

PANDDDKP · 07-11-2016 9:52am

Del2005 wrote: »

How close to the new tyres did you notice the noise and vibrations? What brand are the tyres?

I heard the noise about a month after the tyres were put on. They're Uniroyal Rain Expert 3 tyres. THe only thing to note is the old tyres were 165's, the new ones up front are now 175's. The tyre guy recommended that size... Not sure if that would have a bearing on the issue?

PANDDDKP · 07-11-2016 11:05am

The noise and pedal movement seem to be the ABS. I took out the fuse, and there's no banging now when I stop. The ABS light is on though.

CianRyan · 07-11-2016 2:54pm

If the over all diameter is different it a trigger the ABS at the wrong time, that'd be the second number in the tyre size.

Avatar MIA · 07-11-2016 2:58pm

Not sure if this has been covered by your mechanic before, but the Slave Cylinder not functioning properly (such as a leak) can cause the spongey clutch.

PANDDDKP · 07-11-2016 3:10pm

Avatar MIA wrote: »

Not sure if this has been covered by your mechanic before, but the Slave Cylinder not functioning properly (such as a leak) can cause the spongey clutch.

No he didnt mention that to me..

PANDDDKP · 07-11-2016 3:11pm

CianRyan wrote: »

If the over all diameter is different it a trigger the ABS at the wrong time, that'd be the second number in the tyre size.

The 2 front tyres are the same size as each other, but they're a bit larger than the 2 back tyres.

CianRyan · 07-11-2016 4:17pm

PANDDDKP wrote: »

The 2 front tyres are the same size as each other, but they're a bit larger than the 2 back tyres.

Yep, a bigger sidewall than factory would mean an overall largest diameter, which in turn could cause the fault.

PANDDDKP · 07-11-2016 5:48pm

CianRyan wrote: »

Yep, a bigger sidewall than factory would mean an overall largest diameter, which in turn could cause the fault.

Just spoke with him, he said the bigger tyre would have nothing to do with the abs, so I dunno whats what.. He said the computer would show up a sensor fault but it didn't , so he said it's probably the pump!

LaVail · 07-11-2016 5:50pm

ABS sensor... I'm 90% sure.

edit.. Just saw that he plugged it in and it showed no fault but your opening post sounds exactly like a faulty ABS sensor. I know because it happened my passat a few months back. Fine while braking from higher speeds but when nearly stationary the pedal would jump up and make grinding noises. Felt like something was loose like the caliper but it wasn't. Dangerous when moving in slow traffic.

PANDDDKP · 07-11-2016 5:51pm

LaVail wrote: »

ABS sensor... I'm 90% sure.

Would the computer not show a fault? Even the dash has no light on it.. Dirty sensor maybe?

LaVail · 07-11-2016 5:55pm

PANDDDKP wrote: »

Would the computer not show a fault? Even the dash has no light on it.. Dirty sensor maybe?

Just edited my last post before seeing this one. Dirty sensor was my cause in the finish so no harm in getting it looked at.

martinr5232 · 07-11-2016 9:40pm

PANDDDKP wrote:

Just spoke with him, he said the bigger tyre would have nothing to do with the abs, so I dunno whats what.. He said the computer would show up a sensor fault but it didn't , so he said it's probably the pump!

Dont let him go replacing the pump.
First thing i would check would be vehicle speed on each wheel while driving and braking one wheel looks like its skidding thats why abs is kicking in.
Had the same thing years ago on a mondeo the magnetic strip on the bearing was damaged.

debabyjesus · 07-11-2016 10:46pm

Change the tyres so they are all the same size. Check the abs sensors for cleanliness, check tone rings on outer cj joint for damage/cleanliness. Bleed brakes. Find a new mechanic.

The abs will see different diameter tyres as different wheel speeds and assume wheels are locking if there is a big enough difference.

Slight damage or dirt on a tone ring will often show itself as a pulsing of the abs as you gently slow to a stop.

Exactly what size tyres have you got on the van?

REXER · 08-11-2016 8:51am

I had exactly this problem on a Santa Fe, fine above a crawl speed but banging as the car came to a stop.

It turned out that the toothed gear on one of the front wheels (on the CV joint) that the sensor picks up on had split so there was a extra gap between 2 teeth of about 2-3 mils, not an issue at any sort of speed but sensed as a locked wheel as the car was coming to a stop.

Replaced the gear and the problem was sorted.

PANDDDKP · 08-11-2016 9:18am

debabyjesus wrote: »

Change the tyres so they are all the same size. Check the abs sensors for cleanliness, check tone rings on outer cj joint for damage/cleanliness. Bleed brakes. Find a new mechanic.

The abs will see different diameter tyres as different wheel speeds and assume wheels are locking if there is a big enough difference.

Slight damage or dirt on a tone ring will often show itself as a pulsing of the abs as you gently slow to a stop.

Exactly what size tyres have you got on the van?

The 2 front tyres are 195/60/15 and the 2 back tyres are 185/60/15

The van had all 4 tyres at 185/60/15 and then in July I needed 2 front tyres, the tyre guy said to put 195/60/15 on the front, saying the wheels could take it and it'd give me more grip..

PANDDDKP · 08-11-2016 9:21am

REXER wrote: »

I had exactly this problem on a Santa Fe, fine above a crawl speed but banging as the car came to a stop.

It turned out that the toothed gear on one of the front wheels (on the CV joint) that the sensor picks up on had split so there was a extra gap between 2 teeth of about 2-3 mils, not an issue at any sort of speed but sensed as a locked wheel as the car was coming to a stop.

Replaced the gear and the problem was sorted.

A few videos I saw on ouTube mentioned the same problem. I'll mention it to him. I said to look at sensors etc but he said waste of time, pump is shagged :rolleyes:

tossy · 08-11-2016 9:26am

PANDDDKP wrote: »

A few videos I saw on ouTube mentioned the same problem. I'll mention it to him. I said to look at sensors etc but he said waste of time, pump is shagged :rolleyes:

The fact its kicking in should tell you the pump is working fine. I think your mechanic is shagged

08-11-2016 10:04am

PANDDDKP wrote: »

A few videos I saw on ouTube mentioned the same problem. I'll mention it to him. I said to look at sensors etc but he said waste of time, pump is shagged :rolleyes:

As Tossy says below the fact that the ABS is working shows the pump is working.
Go to a different mechanic.
BTW if the brake pedal is going to the ground the master cylinder might be shagged . This could be due to you mechanic too. Normal use of the brake pedal is an inch or 2 of travel. When bleeding the brakes you push it to the floor numerous times. There can be corosion/scoring on the inside of the master cylinder which damages the seal when bleeding it but does no damage during normal use. Best way to bleed is with a vacuum kit.
Personally i would like to see the van with the same size tyres all around.
Logically the ABS is looking at the speed/number of revolutions of the hubs. With different size wheels the hubs are rotating at different speeds. When you brake it confuses the abs

debabyjesus · 08-11-2016 10:14am

185/60 to 195/60 will be over half an inch bigger diameter if the 185 is a bit worn and the 195 is new. I'd be going back to the tyre place and telling him you've had abs problems since fitting different size tyres and you want the same size all round. Why would a tyre place recommend fitting different size tyres??? Get a new mechanic and a new tyre shop.

A big difference in diameter will likely knock off the abs. A smaller but still significant difference in diameter can cause these little issues and confuse abs, in my opinion. Put on a set of wheels off another yoke and drive it. That will tell you if it's the wheels or not.

PANDDDKP · 08-11-2016 10:37am

debabyjesus wrote: »

185/60 to 195/60 will be over half an inch bigger diameter if the 185 is a bit worn and the 195 is new. I'd be going back to the tyre place and telling him you've had abs problems since fitting different size tyres and you want the same size all round. Why would a tyre place recommend fitting different size tyres??? Get a new mechanic and a new tyre shop.

A big difference in diameter will likely knock off the abs. A smaller but still significant difference in diameter can cause these little issues and confuse abs, in my opinion. Put on a set of wheels off another yoke and drive it. That will tell you if it's the wheels or not.

I don't know what's wrong with all these tradesmen that they're such bloody spoofers. I work in a trade myself and I try to be as honest as possible with people who hire me.. The brakes were perfect when I dropped it off to mechanic, except the abs problem, but now I have new brakes all round, and they don't even work :mad: Basically the brakes are worse now than they ever were..

martinr5232 · 08-11-2016 10:54am

debabyjesus wrote:

185/60 to 195/60 will be over half an inch bigger diameter if the 185 is a bit worn and the 195 is new. I'd be going back to the tyre place and telling him you've had abs problems since fitting different size tyres and you want the same size all round. Why would a tyre place recommend fitting different size tyres??? Get a new mechanic and a new tyre shop.

Width of a tyre wont make any difference to abs circumference will because it will register a different wheelspeed.

OP you really need a different mechanic this lad really doesnt seem to have a clue hes left your van in a worse state than when you first left it to him and its not getting any better by the looks of it.
Numerous posters have told you about experiance with sensors and pick up rings thats where i would be looking.

It should only take a small drive and read the wheel speed at all wheels to locate your problem any competant mechanic should fix that fairly handy to be honest.

debabyjesus · 08-11-2016 11:26am

Changing width is changing diameter and will change wheel speed. It's an easy thing to eliminate before you examine tone rings and sensors op.

PANDDDKP · 08-11-2016 11:52am

debabyjesus wrote: »

Changing width is changing diameter and will change wheel speed. It's an easy thing to eliminate before you examine tone rings and sensors op.

The only thing I can say is I didn't notice the abs kicking when I got the tyres changed. I only noticed a month or so later.
The day I noticed it was the day I got it back from a different mechanic, he was looking at a seperate problem (coolant issue), so while the van was in to him I asked him to check the pads as I had a DOE coming up. He said brakes were fine. Since that day the abs was grinding when I came to a stop, that was a month or so after the tyres were changed.

debabyjesus · 08-11-2016 11:57am

Fair enough op, I thought you mentioned earlier that it started after putting on different size tyres front to back. As martin said earlier if you bring it to a decent mechanic it'll be sorted in no time. Good luck getting it sorted.

PANDDDKP · 08-11-2016 12:57pm

I'll have a look at the abs sensors myself. Are there ones on each front wheel?

martinr5232 · 08-11-2016 1:56pm

debabyjesus wrote:

Changing width is changing diameter and will change wheel speed. It's an easy thing to eliminate before you examine tone rings and sensors op.

Thats like saying new tyres are changing the diameter maybe it does but its not enough to cause an issue if it did there would be abs lights on everytime you replaced two tyres and left half worn tyres on the rear.

185 is the tyre width ie the bit that sits on the road the 65 is the size of the tyre wall and the 16 is the overall diameter.
Tyre width should not be causing that issue i would be looking at pick up rings if it was a sensor issue it should bring on a light.

debabyjesus · 08-11-2016 2:49pm

martinr5232 wrote: »

Thats like saying new tyres are changing the diameter maybe it does but its not enough to cause an issue if it did there would be abs lights on everytime you replaced two tyres and left half worn tyres on the rear.

185 is the tyre width ie the bit that sits on the road the 65 is the size of the tyre wall and the 16 is the overall diameter.
Tyre width should not be causing that issue i would be looking at pick up rings if it was a sensor issue it should bring on a light.

Are you saying 185/60/15 is the same diameter as a 195/60/15??

185/60/15, 185 is the tyre width in mm. 60 is the percentage of 185mm for the sidewall. 15 is the rim in inches.

So changing from a 185/60/15 to 195/60/15 makes the diameter bigger. 60% of 195mm is bigger than 60% of 185mm.

Its not much but have a worn 185/60 on the rear and put new 195/60 on the front and and you have over half an inch bigger diameter difference between front and back.

Is it enough to cause abs issues? Maybe, maybe not.

PANDDDKP · 08-11-2016 3:09pm

I won't be getting the van back til THursday as he's waiting for a replacement cylinder. I asked him to check the abs sensors, he plugged his computer up and it showed no faults.. I'll have to wait until Thursday and see.

martinr5232 · 08-11-2016 3:31pm

debabyjesus wrote:

Are you saying 185/60/15 is the same diameter as a 195/60/15??

Obviously its not but its not worth talking about 6mm if an abs system was that sensitive we would have lights on in all cars once they do ten thousand miles and wear down the front tyres.

debabyjesus wrote:

Is it enough to cause abs issues? Maybe, maybe not.

Highly unlikely op said he had the tyres on a while before this started.

PANDDDKP wrote:

I won't be getting the van back til THursday as he's waiting for a replacement cylinder. I asked him to check the abs sensors, he plugged his computer up and it showed no faults.. I'll have to wait until Thursday and see.

Its not faults you need to look for its the wheel speed from each sensor in real time when driving.
If a sensor was faulty it would usually throw up a light there is no inbetween with them they usually work or they dont its what the sensor picks up from that needs investigating.

PANDDDKP · 08-11-2016 3:35pm

martinr5232 wrote: »

Obviously its not but its not worth talking about 6mm if an abs system was that sensitive we would have lights on in all cars once they do ten thousand miles and wear down the front tyres.

Highly unlikely op said he had the tyres on a while before this started.

Its not faults you need to look for its the wheel speed from each sensor in real time when driving.
If a sensor was faulty it would usually throw up a light there is no inbetween with them they usually work or they dont its what the sensor picks up from that needs investigating.

He had the computer plugged in while driving a few days ago, we drove 3 miles, no issue showed up. Would it show up on the computer when driving?

Special Circumstances · 08-11-2016 3:38pm

PANDDDKP wrote: »

He had the computer plugged in while driving a few days ago, we drove 3 miles, no issue showed up. Would it show up on the computer when driving?

I suspect the answer is something along the lines of "It would if you knew what you were looking for!"

debabyjesus · 08-11-2016 3:38pm

6mm? Try again.

OP good luck getting the car sorted but I'd be getting it out of wherever it is before you're hit with a big bill for what's likely a simple defect.

martinr5232 · 08-11-2016 3:39pm

PANDDDKP wrote:

He had the computer plugged in while driving a few days ago, we drove 3 miles, no issue showed up. Would it show up on the computer when driving?

Its real time data you need in a graph to see where its breaking down just checking for faults is no good because the abs is working and doing what it thinks is right with the information its recieving.

My brakes are driving me nuts..

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