Help please bleeding brakes

[steve j]

Okay, I`ve put upgraded brakes on the front i,e, Griff discs and calipers. The brakes stood empty for a few months whilst I tarted the front end up. Now I can`t get the brakes to work, I can bleed the rear and feel a release of pressure on the pedal when the nipple is released, but not on the front. I`ve been informed that the master cylinder may now not work . Surely then the rear brakes wouldn`t get pressure to them. Can someone please give me a heads up as i`m trying to get her ready for S club, cheers in advance.
Stevej

[Barkychoc]

Steve the front and rear hydraulic circuits have seperate seals - so if one set fails you still have pressure to the other circuit, I'm not a master cylinder expert but it sounds like it could be the front seals, have you tried an easibleed kit to bleed them?

[steve j]

Hi Chris, tried the easibleed route and couldn`t get an airtight seal on the reservoir. So it looks like another master cylinder is on the cards, I suspected that there might be two sets of seals on the cylinder but only one bleed nipple and that threw me, cheers mate, hopefully I`ll have it ready for next weekend

[Barkychoc]

When using the tyre as a pressure source you need to let it down quite a bit - I can't remember what the instructions say but if you're using the tyre as is the pressure may be too high.

[steve j]

Chris, 20 p.s.i. is the norm, but as I couldn`t feel any pressure release at the pedal I now suspect the cylinder, I`ll try again tommorow starting with scourcing another cylinder.

[Tant]

Steve

eesibleeds can be a bit of a bugger to seal sometimes. I have just done my brakes using an eesibleed which I have had few a few years now..

A few things I have learned with mine..

1. Reduce the tyre pressure a bit..probably about 20-25PSI is about right.
2. The seal on the fluid resevoir sometimes gets squeezed down too far...just make sure it is well seated in the cap, and don't do it too tight as overtightening pushes the seal into the bottle.
3. Same with the seal on your master cylinder cap...doesn't like being overtightened.Make sure it's the right one, and wet it slightly with brake fluid to stop it twisting.
4. Don't overfill the bottle..but keep a close eye on it for level.
5. Keep plenty of rags and a watering can/hose near by in case you need to clear up any spillages.
6. Always use clear tube on the bleed nipples so you can see when the bubbles stop, otherwise you waste a fair bit of fluid.
7. Start at the point furthest away from master cylinder (NSR) and work you way closer..


Hope that helps...and it's not telling you how to suck eggs

Cheers

Ant

[steve j]

Tant said:

Steve

eesibleeds can be a bit of a bugger to seal sometimes. I have just done my brakes using an eesibleed which I have had few a few years now..

A few things I have learned with mine..

1. Reduce the tyre pressure a bit..probably about 20-25PSI is about right.
2. The seal on the fluid resevoir sometimes gets squeezed down too far...just make sure it is well seated in the cap, and don't do it too tight as overtightening pushes the seal into the bottle.
3. Same with the seal on your master cylinder cap...doesn't like being overtightened.Make sure it's the right one, and wet it slightly with brake fluid to stop it twisting.
4. Don't overfill the bottle..but keep a close eye on it for level.
5. Keep plenty of rags and a watering can/hose near by in case you need to clear up any spillages.
6. Always use clear tube on the bleed nipples so you can see when the bubbles stop, otherwise you waste a fair bit of fluid.
7. Start at the point furthest away from master cylinder (NSR) and work you way closer..


Hope that helps...and it's not telling you how to suck eggs

Cheers

Ant

Cheers Tant, most helpful, I tried the easibleed and found it in this situation rather poor, due to the fact that the seals in the cylinder may have gone, so I`ll soldier on.

[Tant]

OK Steve


Have you tried disconnecting a front pipe and see if fluid comes out under pressure when you press the pedal. When it was laid up, was there fluid in the master cylinder.

In any case, master cylinders aren't that expensive if you are sure it's that, but the brakes can take a few rounds of bleeding when you change it.

Cheers

Ant

[mep12345]

Have you also cleared the air in the MC using the bleed nipple on the cylinder. This is on the rear circuit, but with mine this (and the balance valve) caused air locks and stopped me bleeding properly (albeit the rear circuit not the front). Before changing the MC I would crack the unions at the master cylinder and try to bleed through this first. This will ensure the MC is full of fluid and then allow you to fill and bleed the pipes.

Make sure you have lots of rags and water though

Of course if you crack each union in turn and get nothing out then the MC is definitely shot and you've diagnosed the problem 100%

HTH

Mark

[steve j]

Tant said:

OK Steve


Have you tried disconnecting a front pipe and see if fluid comes out under pressure when you press the pedal. When it was laid up, was there fluid in the master cylinder.

In any case, master cylinders aren't that expensive if you are sure it's that, but the brakes can take a few rounds of bleeding when you change it.

Cheers

Ant

Fluid does indeed come out from the front, as I`ve put new copper pipes on at the caliper, I can only assume that fluid was in the cylinder when it was laid up, surely it wouldn`t dry out in the space of a month or two. Fluid is getting through to the bleed nipple but not under pressure, I still suspect cylinder seals and the pedal action sounds squelchy when listening under the bonnet, if that makes sense.

[steve j]

Update, still no brakes, I`ve fitted another master cylinder and tried all over again Looks like it`s staying in the garage now !!!!! I`m sick of brake fluid on my hands, nearly given up on the bl%$#dy thing. Looks like the oil burner for SCH

[Tant]

what happened why you tried this time Steve?
What did you do once the new master cylinder was fitted. When I did mine, I filled the resevoir with fluid, operated the pedal by hand to take it through a few strokes gently, while I had the unions just cracked. Then tightened everything up, filled it again, and then it took me 3 rounds of the car with the eezibleed to get all the air out.

....how is is behaving now?

cheers

Ant

[steve j]

Tant said:

what happened why you tried this time Steve?
What did you do once the new master cylinder was fitted. When I did mine, I filled the resevoir with fluid, operated the pedal by hand to take it through a few strokes gently, while I had the unions just cracked. Then tightened everything up, filled it again, and then it took me 3 rounds of the car with the eezibleed to get all the air out.

....how is is behaving now?

cheers

Ant

Hi Tant, I`ve given up today, sick of brake fluid and my heart isn`t in it so I may have another go tommorow. Got fluid at the unions and then just gave up trying really.

[spludge]

steve j said:

I can bleed the rear and feel a release of pressure on the pedal when the nipple is released, but not on the front.

Do you get that on both sides and is it still like that with the new master cylinder? If so I'd check the flex hoses, are they in good condition and didn't get kinked or twisted when the new calipers were fitted.

K

[ketvrin]

If you over tightened the union nut when you fitted the new copper pipes on the front its possible you have squished the end too much and have effectively closed it off... if all else fails, it wouldnt take much to remove them to check there is a hole in the end of your pipe... easy fixed if its that too

good luck - you dont really want to turn up at SCH in an oilburner do you ? who'll take noisiest exhaust ???

K

[Adrian@]

Using your easi-bleed...try venting the master cylinders at the connections and raising the car (with a mind on doing this safely) on the front drivers side corner and then bleeding it again.
Adrian@

[steve j]

Thanks fellas for your thoughts, my father is coming over with a different type of bleed kit and try again, the thought of driving to SCH in the tin top isn`t to bad but it`s not the same is it

[phillpot]

Nothing more i can add to the advice you've already had except its gotta be something daft and you'll probably kick yourself when you sort it !

Good luck' sure you'll get it to SCH

[Griffinr]

Another trick to try is as follows; Assuming you have some fluid in the front calipers you could try a bit of backwards bleeding. Force the front pistons back into the calipers which will drive the fluid and any air back up through the mastercylinder into the reservoir. I have used this trick when changing brake pipes and finding the bleed nipple seized on the caliper.

Hope you get sorted.

Rob.

[steve j]

Update fellas, got fluid at all four corners using the easibleed but the pedal still goes to the floor. I have air at the servo too so I`m just going top have to try again. My daily hack has just started to play up as well, It`s a diesel with starting problems, new glowplugs didn`t sort it so it might be a solenoid, ah well two cars to sort out