Brake Problems

cian1500ww

Having some problems with the brakes on a 1955 Austin A30. There was little or no stopping power with the brake pedal pushed firmly to the floor. I suspected that the master cylinder would need new seals so I went ahead and changed the seals in it but it doesn't seem to have made any difference. The pedal still goes flat to the floor albeit under pressure but the wheel cylinders on the front don't budge.
The A30 also has a rear frame cylinder for the back brakes so I think that might be my next port of call.
Has anyone had any similar issues with the brake pedal going to the floor and the wheel cylinders not budging ?? It would seem like a leak in pressure but there are no leaks from what I can see.
I haven't bled the system yet either.

kasper

unless the front pistons are seized they should make some attempt to stop the car , bleed the brakes and that will determine if the master cylinder is actually pushing the fluid to the wheels .

cian1500ww

kasper wrote: »

unless the front pistons are seized they should make some attempt to stop the car , bleed the brakes and that will determine if the master cylinder is actually pushing the fluid to the wheels .

It's definetly pushing the fluid to the front cylinders as i found out the hard way (left a pipe disconnected :rolleyes:). I have the hubs off and I can see the front wheel cylinders and they're not budging at all.
They might be seized but I haven't had any luck in getting them apart yet to fit new seals.

Slidey

If you have fluid traveling to the cylinders and they are not moving they are more than likely siezed.

A good way of getting them moving if they are stuck is to take off the brake pipe and screw in a grease nipple and pump them out with a grease gun. once one side of the cylinder starts to move stop that side and get the other side moving or else you will only get one out!

kasper

is it drums or discs on the front ?

cian1500ww

Slidey wrote: »

If you have fluid traveling to the cylinders and they are not moving they are more than likely siezed.

A good way of getting them moving if they are stuck is to take off the brake pipe and screw in a grease nipple and pump them out with a grease gun. once one side of the cylinder starts to move stop that side and get the other side moving or else you will only get one out!

Interesting idea with the grease gun, I'll give that a try anyway. The weird thing is, there's 4 cylinders on the front and none of them are budging, is it possible that all of them could be seized or would just one stop the whole lot from working ??

kasper wrote: »

is it drums or discs on the front ?

Drums all round.

Slidey

It is quite possible they are all seized if it has been parked a while

Wheelnut

cian1500ww wrote: »

It's definetly pushing the fluid to the front cylinders as i found out the hard way (left a pipe disconnected :rolleyes:). ..

That doesn't mean that the system is free of air. There was no resistance to flow with the pipe disconnected so the fluid came. When the pipe is connected there will be resistance to flow and if there is air in the system it will compress. Bleed the system first and then start trying other solutions. Let us know how you get on.

Wheelnut

Slidey wrote: »

A good way of getting them moving if they are stuck is to take off the brake pipe and screw in a grease nipple and pump them out with a grease gun.

Are you pumping grease into the cylinder or are you somehow putting brake fluid in a grease gun? I would think that pumping in grease is highly dangerous because it may react with the rubber of the seals and cause them to fail. I would advise against this trick unless you are going to rebuild the cylinders with new seals. Why not use compressed air through the nipple? Sometimes even the pressure from a foot pump will do the job.

aujopimur

I recommend replacing the wheel cylinders as they are not very expensive and are easily sourced.
Google wheel brake cylinders, you'll find its not much more expensive to replace than to repair.

kasper

aujopimur wrote: »

I recommend replacing the wheel cylinders as they are not very expensive and are easily sourced.
Google wheel brake cylinders, you'll find its not much more expensive to replace than to repair.

that is the way i would be thinking as well seeing as the new seals have being done on the master cylinder every thing would be fresh and reliable

Slidey

Wheelnut wrote: »

Are you pumping grease into the cylinder or are you somehow putting brake fluid in a grease gun? I would think that pumping in grease is highly dangerous because it may react with the rubber of the seals and cause them to fail. I would advise against this trick unless you are going to rebuild the cylinders with new seals. Why not use compressed air through the nipple? Sometimes even the pressure from a foot pump will do the job.

I am aware of that. If they are seized they will need new seals. Compressed air to move a stuck brake piston... not a fecking hope.

If you can move them with compressed air or a footpump, they are not stuck!

The grease gun trick is handy as the nipples have the same thread as the wheel cylinders and there is a lot of force in a pumped grease gun

cian1500ww

Wheelnut wrote: »

That doesn't mean that the system is free of air. There was no resistance to flow with the pipe disconnected so the fluid came. When the pipe is connected there will be resistance to flow and if there is air in the system it will compress. Bleed the system first and then start trying other solutions. Let us know how you get on.

Bleeding is definitely on the agenda, just need a second person to help me with that.

aujopimur wrote: »

I recommend replacing the wheel cylinders as they are not very expensive and are easily sourced.
Google wheel brake cylinders, you'll find its not much more expensive to replace than to repair.

I checked prices on replacing the cylinders and was quoted about £70 (Sterling) for a wheel cylinder in exchange. I have the rebuild kit for the cylinder but they're proving to be a proper b***h to get apart.

JoeySully

cian1500ww wrote: »

Bleeding is definitely on the agenda, just need a second person to help me with that.

Get down to halfords and get one of these
http://www.halfords.ie/webapp/wcs/stores/servlet/product_storeId_11101_catalogId_15551_productId_204645_langId_-1_categoryId_212616

or the cheaper version is just as good
http://www.halfords.ie/webapp/wcs/stores/servlet/product_storeId_11101_catalogId_15551_productId_204703_langId_-1_categoryId_212616

Will save you a lot of time and no mess!

ozf

cian1500ww wrote: »

Bleeding is definitely on the agenda, just need a second person to help me with that.


I checked prices on replacing the cylinders and was quoted about £70 (Sterling) for a wheel cylinder in exchange. I have the rebuild kit for the cylinder but they're proving to be a proper b***h to get apart.

Send me the old cylinders & kits & I'll rebuild them for you..I also have a frame cylinder kit Lockheed no: KL 71503, send it also & I'll rebuild the lot.
PM me if required.

Wheelnut

Ignore all other advice until you bleed the system (but keep it for reference). I just find it hard to believe that all four cylinders in the front brakes would seize simultaneously. There are other possible simple solutions that I was hoping to come to systematically. For instance, the adjustment of the rear brakes could be backed off too far so that all the movement of the master cylinder is taken up just pushing the rear shoes into contact with the drums. In some systems a badly adjusted handbrake will have a similar effect. So just bleed the system first and see what happens, you can take all the other suggestions in turn.

cian1500ww

ozf wrote: »

Send me the old cylinders & kits & I'll rebuild them for you..I also have a frame cylinder kit Lockheed no: KL 71503, send it also & I'll rebuild the lot.
PM me if required.

I'll rebuild them myself but thanks for the offer.

Wheelnut wrote: »

Ignore all other advice until you bleed the system (but keep it for reference). I just find it hard to believe that all four cylinders in the front brakes would seize simultaneously. There are other possible simple solutions that I was hoping to come to systematically. For instance, the adjustment of the rear brakes could be backed off too far so that all the movement of the master cylinder is taken up just pushing the rear shoes into contact with the drums. In some systems a badly adjusted handbrake will have a similar effect. So just bleed the system first and see what happens, you can take all the other suggestions in turn.

I'll bleed the system as soon as I can, do I just wait until there's no more bubbles in the fluid that leaves through the pipe that's attached to the cylinders ?

kasper

if you get a tight fitting pipe i have used the pipe off windscreen washer jets and a jam jar you can bleed the brakes unassisted . firstly cover the bottom of the jar with brake fluid , fit the pipe on the open bleeder and the other end into jar below fluid level line ,starting at wheel nearest master cylinder , keep the resovoir topped up at all times , pump brake pedal until all air has stopped in jar and then tighten that bleed nipple , work your way round car until complete .. make sure not to un- nescerally shake brake fluid that is being used to top up resiover . dont use brake fluid caught in jar as it will have air in it . dont let brake fluid to get in contact with paintwork on car ..

Wheelnut

cian1500ww wrote: »

... do I just wait until there's no more bubbles in the fluid that leaves through the pipe that's attached to the cylinders ?

There may be some confusion here, but just in case.... you don't open the union on the pipe attached to the cylinders. You open the bleed nipple having placed a piece of plastic tubing on it as advised by Kasper.

Sorry if I misunderstood.

PS @ Kasper: PM sent today.

cian1500ww

Wheelnut wrote: »

There may be some confusion here, but just in case.... you don't open the union on the pipe attached to the cylinders. You open the bleed nipple having placed a piece of plastic tubing on it as advised by Kasper.

Sorry if I misunderstood.

Yep, that's what I meant, I'm having trouble finding a clear pipe that'll fit over the bleed nipple. Can't seem to get any washer pipes onto it either.

cian1500ww

This is what the front hubs look like:

kasper

it doesnt have to be a clear pipe that fits over the bleed nipple ,its just easier to see the air in the fluid if you have the last time i bled brakes i used a vacuum pipe off a car . the bleed nipples are at the back of the brake cylinders on each wheel . the pipe just has to be snug fitting about a 6-8 mm bore . its just the pipe cant be used for its original task after it has been used for beake fluid .......

8~)

Have to agree with the lads - bleed the brakes first. Judging by your description I could almost guarantee there is air in there. You do need two people too; one to pump one to study the fluid and air bubbles exiting the pipe in order to know when the air is removed. No point trying to bleed them alone - you'll spend all day running around the car.

kasper

well cian any progress on the anchors ? if i am not a million miles away from you i could pop over tomorrow or any evening

cian1500ww

kasper wrote: »

well cian any progress on the anchors ? if i am not a million miles away from you i could pop over tomorrow or any evening

No progress as of yet, hoping to get the bleeding done tomorrow evening all going well. Kind of you to offer but I think I should be ok, thanks anyway !!

cian1500ww

Bled the front hubs and the pedal seems to have a better feel to it now, still can't get the wheel cylinders to budge though, they must be seized. How do you take them apart ??

Slidey

So long as you are replacing the seals the grease gun is the easiest way IMO

Wheelnut

In the photo you posted it looks like part of the piston is protruding from the cylinder. Can you not try to pull it or push it with your fingers? You may need a pliers to pull it. If they are rock solid they are seized.