Fitted new calipers - no fluid coming from one

spockety

Fitted a pair of new calipers today.. have done it a few times before on different cars no problem.

Fitted first one, bled brakes, no problem.

Fitted second one, tried to bleed brakes but no fluid coming out bleed valve.

Took off caliper and pressed brake pedal plenty of times... a smidgen of fluid came out the brake hose but then nothing nada zip.

Brake pedal travels to the floor now and brake effort is not exactly good.

Car is a 2000 Mazda 323F hatchback.

Am I looking at a master cylinder issue here? If so, is it reasonable that the problem only reared it's head after replacing the calipers? The two original calipers were shot, both seized and one had brake pad worn to the bone and grinding off the disc etc.

Rear are drums, haven't touched.

Other thing to note that may or may not be relevant is that the car was on a slightly inclined driveway when this was being done, with the front of the car up on the higher end and then also jacked up.

I'm off the road now until I get this sorted so any advice would be very much appreciated. Before now my knowledge of braking systems ended at the calipers.. I'm not afraid to learn more but would like to get it right.

P.s. It got dark so I had to stop, but the next thing I was going to try was to bleed the first caliper again and see if fluid was coming out of that one still.. is this worth doing? Will it help to pinpoint?

Also, the fluid reservoir hasn't been going down so I don't think it's a leak.

88manta

are you pressurising the reservoir?

or is someone pumping pedal for you?

spockety

2nd person pumping the pedal

timmy4u2

Do you have abs as some of these cars have abs and it might help to start the engine in case the ecu is causing the problem. Could also be airlocked in the abs unit.

If it does not have abs we will have to go back to the drawing board and look at whether you pressed the pistons back and turned the rubbers in the master cylinder.
Used to be a big problm with the Opels.

spockety

Pretty sure it has abs as the brake lines from the master cylinder go to another unit with electrical connectors first..

timmy4u2

spockety wrote: »

Pretty sure it has abs as the brake lines from the master cylinder go to another unit with electrical connectors first..

I would zero in on that for starters. Even inadvertantly turning one wheel while the ignition is on can send a signal to the abs unit and it would stop the fluid being sent to the other wheel.
Maybe not but has happened in the past.

spockety

Well I was turning the wheels with the ignition on alright once I'd popped the wheels off to give easier access to the calipers...

timmy4u2

spockety wrote: »

Well I was turning the wheels with the ignition on alright once I'd popped the wheels off to give easier access to the calipers...

The plot thickens. It is never just a simple task that causes the problems.
I would certainly have a good luck at the abs unit under those circumstances.

keithsfleet

You've taken the cap off the brake fluid reservoir?

spockety

How does the ABS unit work? Does it stop the flow of fluid to particular wheels?

Is the suggestion that I try to bleed the first caliper again to see if fluid continues to come out that?

Then check each outlet from the ABS pump? As in loosen the brake line from each ABS unit outlet and see if fluid comes from there when the pedal is pressed?

Presumably this is all still with the ignition off?

There are no ABS warning lights or anything on the console that I noticed..

spockety

keithsfleet wrote: »

You've taken the cap off the brake fluid reservoir?

Cap on tight while bleeding..

Don't tell me it's meant to be off?

keithsfleet

Yup needs to be screwed loose.

The vacumn inside it will prevent it from going down. Cap could be very tight at this stage so make sure to hold the reservoir while turning the cap.

spockety

keithsfleet wrote: »

Yup needs to be screwed loose.

The vacumn inside it will prevent it from going down. Cap could be very tight at this stage so make sure to hold the reservoir while turning the cap.

If it's something as simple as that obviously I will be ecstatic

Is it really that likely a culprit??

timmy4u2

spockety wrote: »

How does the ABS unit work? Does it stop the flow of fluid to particular wheels?

Is the suggestion that I try to bleed the first caliper again to see if fluid continues to come out that?

Then check each outlet from the ABS pump? As in loosen the brake line from each ABS unit outlet and see if fluid comes from there when the pedal is pressed?

Presumably this is all still with the ignition off?

There are no ABS warning lights or anything on the console that I noticed..

There would not be a warning light on if the ecu thinks it is doing a good job.

The most popular system is a sensor and a valve for each wheel.
The sensor on the wheel picks up the movement of the wheel and the ecu then decides to do one of three things.
It will stop the flow totally to the wheel.
It will allow the fluid straight through or it will allow a limited amount of fluid through.
Be careful loosening the unions as they are going into aluminium.
Bleed on the outlet with gentle pressure on the pedal. Do not whack it down.
If it does not work with the ignition off try with it switched on.
Some abs units have a bleed nipple on the top.

spockety

timmy4u2 wrote: »

There would not be a warning light on if the ecu thinks it is doing a good job.

The most popular system is a sensor and a valve for each wheel.
The sensor on the wheel picks up the movement of the wheel and the ecu then decides to do one of three things.
It will stop the flow totally to the wheel.
It will allow the fluid straight through or it will allow a limited amount of fluid through.
Be careful loosening the unions as they are going into aluminium.
Bleed on the outlet with gentle pressure on the pedal. Do not whack it down.
If it does not work with the ignition off try with it switched on.
Some abs units have a bleed nipple on the top.

Thanks very much for that.

Could it then possibly be a faulty sensor at the affected wheel...?

timmy4u2

spockety wrote: »

If it's something as simple as that obviously I will be ecstatic

Is it really that likely a culprit??

I thought you were joking when you responded at first to that question. Although there should be enough air getting in as if not the fluid would not follow down into the caliper as the pads wear.
Now if you are serious it begs the second question, and thatvis did you top up the brake fluid as you bled the system

keithsfleet

spockety wrote: »

If it's something as simple as that obviously I will be ecstatic

Is it really that likely a culprit??

Yes.

The reason you were able to bleed the first side was there was no vacumn inside the reservoir.

When you moved to the other side you managed to get a little fluid out but then the vacumn became to much in the reservoir.

spockety

Cap was removed at regular intervals when doing the first side in order to keep the levels topped up.

There was actually some disagreement between myself and my bleeding companion as to whether the lid should stay on or off... we went with his preference to leave it on..

At the end of the day just before we finished we tried pumping the brake pedal with the lid off the reservoir, to see if fluid would rise out the top but it didn't..

timmy4u2

spockety wrote: »

Thanks very much for that.

Could it then possibly be a faulty sensor at the affected wheel...?

No it would be an active sensor sensing that the other wheel was stopped and the valve would then close off the pipe to that wheel.
But I would check the cap on scenario first just in case the cap did not have enough leeway to allow an amount of fluid to go down.
Brake fluid is hygroscopic in that it absorbs water so the resevoir attempts to keep out the moisture and to compensate the inside of the cap expands as the fluid goes down.
Synthetic brake fluid is not but it is not used in older cars as it can affect the seals.

two wheels good

There may be a bleed nipple on the ABS unit. Probably worth bleeding there too.

spockety

Doing a bit more research.. what make you of this? I was using a hose clamp alright..

From http://www.club323f.com/forum/viewtopic.php?f=38&t=55606

I had a similar problem on my focus, it only affected one caliper. It turned out to be a flexi hose. According to the owner of brakes international, it was caused by using a hose clamp. Apparently this weakens the inner lining of the flexi pipe, and can cause "flaps" inside the pipe which can operate a bit like a one way valve. After changing the offending flexi, I never had that problem again.

We cut the pipe in half (length ways) and sure enough there were signs of damage to the inner walls of the pipe, some of which had started to cause the flaps Ray was talking about

timmy4u2

spockety wrote: »

Doing a bit more research.. what make you of this? I was using a hose clamp alright..

From http://www.club323f.com/forum/viewtopic.php?f=38&t=55606

There is a very slim chance that it could be a collapsed flexible pipe. Happened occasionally on the rear calipers of the W 114 mercs circa 1973 vintage.
If your flexible pipe was that hard and stiff you would know it as it just would not be flexible.

biko

spockety

Thanks for all the advice so far... a quick update..

Had another go at it this morning. Started by bleeding the first wheel again.. no problem, fluid coming out.

Tried rear wheel.. some fluid coming out but not as much as I would expect.. a dribble.

Tried second rear wheel .. fluid coming out no problem as expected.

Loosened lines exiting from master cylinder one at a time while pressing pedal.. fluid coming out of both.. so seemed to rule out master cylinder.

Couldn't get line off ABS module.. risked rounding off the nut ..

Took the flexible hose from the caliper off at where it meets the brake line (took a lot of persuasion). Pumped the pedal and some fluid came out, but then nothing... though as the pedal was being pumped I could see bubbles appearing so there was definitely pressure of some sort getting to that point.

Decided at this point that maybe the pedal pumping bleeding method was simply not going to give us any joy. Headed to Halfords and bought a Gunson Eezibleed system (uses tyre pressure at the master cylinder reservoir to force fluid down). Anyway, started with the dodgy wheel corner and low and behold the Gunson combined with a few pedal presses and the fluid started flowing down.

Tested the brakes and they work, though they are a bit spongy. I need to now bleed out all the other lines.

Worth noting that the old fluid is absolutely mank. I mean it's the worst I've ever seen, really really terrible. Resorted to syringing some out the top of the master cylinder reservoir it was so bad at the top.

Anyway, in the next few days I will use the Gunson to bleed out all of the other corners, and see where we are.

Cheers folks.

timmy4u2

spockety wrote: »

Thanks for all the advice so far... a quick update..

Had another go at it this morning. Started by bleeding the first wheel again.. no problem, fluid coming out.

Tried rear wheel.. some fluid coming out but not as much as I would expect.. a dribble.

Tried second rear wheel .. fluid coming out no problem as expected.

Loosened lines exiting from master cylinder one at a time while pressing pedal.. fluid coming out of both.. so seemed to rule out master cylinder.

Couldn't get line off ABS module.. risked rounding off the nut ..

Took the flexible hose from the caliper off at where it meets the brake line (took a lot of persuasion). Pumped the pedal and some fluid came out, but then nothing... though as the pedal was being pumped I could see bubbles appearing so there was definitely pressure of some sort getting to that point.

Decided at this point that maybe the pedal pumping bleeding method was simply not going to give us any joy. Headed to Halfords and bought a Gunson Eezibleed system (uses tyre pressure at the master cylinder reservoir to force fluid down). Anyway, started with the dodgy wheel corner and low and behold the Gunson combined with a few pedal presses and the fluid started flowing down.

Tested the brakes and they work, though they are a bit spongy. I need to now bleed out all the other lines.

Worth noting that the old fluid is absolutely mank. I mean it's the worst I've ever seen, really really terrible. Resorted to syringing some out the top of the master cylinder reservoir it was so bad at the top.

Anyway, in the next few days I will use the Gunson to bleed out all of the other corners, and see where we are.

Cheers folks.

Gunson should not have made any difference other than its a one man effort so were you not opening the bleed valves enough.
There should be a bleed valve on top of the abs unit.
If extremely thick gungy fluid was your problen the most likely place for blocking is in the abs unit at the valves.
Drive it, use the brakes and rebleed starting at the furthest away after bleeding the abs unit.

spockety

timmy4u2 wrote: »

Gunson should not have made any difference other than its a one man effort so were you not opening the bleed valves enough.
There should be a bleed valve on top of the abs unit.
If extremely thick gungy fluid was your problen the most likely place for blocking is in the abs unit at the valves.
Drive it, use the brakes and rebleed starting at the furthest away after bleeding the abs unit.

I couldn't see a bleed valve on either of the master cylinder or the ABS unit..

Having said that, the ABS unit is in a really awkward spot.

timmy4u2

spockety wrote: »

I couldn't see a bleed valve on either of the master cylinder or the ABS unit..

Having said that, the ABS unit is in a really awkward spot.

I would not expect you to find one on the master cylinder. No all abs units have them either, if there is it is usually in the middle of the unit.
Good it is working out.

spockety

timmy4u2 wrote: »

I would not expect you to find one on the master cylinder. No all abs units have them either, if there is it is usually in the middle of the unit.
Good it is working out.

Cheers. I will persist with bleeding them all now thoroughly and report back. Hopefully I will be left with a nice stiff brake pedal when pushed.

dgt

No fluid? More than likely the rubber pipe itself has broken down inside and is causing a blockage. Happened to us a few times.

Crack it at the union and see if some fluid comes out there

martinr5232

Is there a brake equalising valve on the back axle try jacking up the wheel your having trouble bleeding to working height or put the wheel on an drop it down on a block of wood then try bleeding it.

timmy4u2

dgt wrote: »

No fluid? More than likely the rubber pipe itself has broken down inside and is causing a blockage. Happened to us a few times.

Crack it at the union and see if some fluid comes out there

We kind of drifted away from that issue having mentioned it earlier, so if the pipe feels as if it is not flexible it may have become brittle inside, but without going back on the thread I think you had the problem with more than one wheel.

spockety

Just a further update to close off.

Used the Gunson Eezibleed to do a full bleed of the entire system to every wheel.. put over a litre of brake fluid in to be sure.

Brakes feel great now, so I think job done. My observation of the fluid coming out leads me to believe that it may very well have been the original from the factory (2000) :eek: :eek:

Something else mind boggling.. had to buy the fluid in Halfords as it was Sunday.. 500ml of fluid ten quid. 5 litres of fluid 22 quid!

Thanks for all the advice/info folks.

timmy4u2

spockety wrote: »

Just a further update to close off.

Used the Gunson Eezibleed to do a full bleed of the entire system to every wheel.. put over a litre of brake fluid in to be sure.

Brakes feel great now, so I think job done. My observation of the fluid coming out leads me to believe that it may very well have been the original from the factory (2000) :eek: :eek:

Something else mind boggling.. had to buy the fluid in Halfords as it was Sunday.. 500ml of fluid ten quid. 5 litres of fluid 22 quid!

Thanks for all the advice/info folks.

Glad it all worked out for you, and of course you got the non synthetic fluid.