brake bleeding help!!!!

[ukApache]

Hi all, I'm having a lot of problems bleeding my brakes and I'd really appreciate it if anyone could give me any clues as to where I'm going wrong....

 

I recently serviced my calipers (cleaned, new seals etc.) but after fitting them back onto the car & bleeding the system I cant seem to get a firm pedal feel

 

So far I've put about ~3.5 ltrs of brake fluid through the system but still the pedal can be pressed completely to the floor with only very little braking effect. I've checked for fluid leaks but cant find any and with the system closed the fluid level in the reservoir stays the same.

 

My car is a 94 N/A with ABS, so i've also tried bleeding it with the engine running. Any suggestions would be greatly appreciated!!!!!

 

Thanks.

[TrickTT]

Double check all your calipers and hoses for fluid leaks and if they are all dry you may have flipped a seal in your master cylinder.

[ukApache]

thanks for the reply!!

 

I've checked all 4 calipers after a lot of pumps on the brake pedal and they're all dry + the level in the reservoir on the master cylinder has not dropped.

 

What exactly do you mean by flipped a seal? How hard/£ is it to fix?

 

Thanks.

[Pete]

Are you doing this on your own or with help? It's nigh on impossible to do a good job of it with one of those on your own kits.

[ukApache]

Are you doing this on your own or with help? It's nigh on impossible to do a good job of it with one of those on your own kits.

 

I have been doing it by myself, like you said using a one man bleeder kit (just a transparent hose with a non-return valve on the end).

 

I have noticed that if I pump the brake pedal continuously with the engine off the pedal firms up slightly, then if I release it for a few seconds and then pump it again the pedal will go completely to the floor

 

It feels just like a leak, but as I said before I checked all calipers + hoses + the level in the reservoir and there is no sign of a fluid leak.

[Pete]

Those kits are pooh, you need a mate.

 

Stick him in the car, open the bleed nipple, shout on, they should slowly depress the brake, the say when at the bottom of travel, you close the nipple, you shout up, they slowly release up, you open nipple, shout on, they slowly...and so on.

 

Once the pedal starts to feel firm do it one last time, but slower if possible with the nipple not fully open.

 

This is pretty much how I did it with my kitcar and with CW the other week. Just watch the reservoir to keep topped up. Should only take 4-5 or so depresses.

 

I'm sure they'll be a guide on the net to show you how to do this.

[ukApache]

Those kits are pooh, you need a mate.

 

Stick him in the car, open the bleed nipple, shout on, they should slowly depress the brake, the say when at the bottom of travel, you close the nipple, you shout up, they slowly release up, you open nipple, shout on, they slowly...and so on.

 

Once the pedal starts to feel firm do it one last time, but slower if possible with the nipple not fully open.

 

This is pretty much how I did it with my kitcar and with CW the other week. Just watch the reservoir to keep topped up. Should only take 4-5 or so depresses.

 

I'm sure they'll be a guide on the net to show you how to do this.

 

Thanks for the advice! so you think that the problem is to do with air trapped in the system? The thing is I bled it 3-4 times and there was no air bubbles in the exit line (apart from the first time).

 

Cheers.

[Graham S]

Those kits are pooh, you need a mate.

 

Stick him in the car, open the bleed nipple, shout on, they should slowly depress the brake, the say when at the bottom of travel, you close the nipple, you shout up, they slowly release up, you open nipple, shout on, they slowly...and so on.

 

Once the pedal starts to feel firm do it one last time, but slower if possible with the nipple not fully open.

 

This is pretty much how I did it with my kitcar and with CW the other week. Just watch the reservoir to keep topped up. Should only take 4-5 or so depresses.

 

I'm sure they'll be a guide on the net to show you how to do this.

 

 

That sounds about right mate, but start from the furthest caliper from the reservior(sp?) so do the nearside rear first (passenger back) the the drivers rear, then the passenger front, then drivers front last.

[Graham S]

Do we have a 'how to bleed brakes guide' here, if not i could always do one?? Mods?

[TrickTT]

thanks for the reply!!

 

I've checked all 4 calipers after a lot of pumps on the brake pedal and they're all dry + the level in the reservoir on the master cylinder has not dropped.

 

What exactly do you mean by flipped a seal? How hard/£ is it to fix?

 

Thanks.

If you pump too quickly on the pedal the seals on the piston in the master cylinder can rotate so they dont seal against the cylinder wall under pressure. If thats the case you need a new or rebuilt master cylinder.

Try bleeding them properly using 2 people and if they are still soft that will be the problem.

[ukApache]

Thanks for all the help guys!

 

I'll try bleeding them as talked about above, but if that doesn't work I'll disassemble the master cylinder and refurb the seals.

 

Anyone know the part number for the MC service kit for an N/A 94 J-spec with ABS, just in case I need it?

 

Cheers

[Mike B]

I'm having a few brake probs myself at the moment, glad to see I'm not alone. I have a slightly squishy feel, but not as bad as yours.

 

Like you I have bled myself, completely changing the fluid, without improvement so I'm employing the services of a chum this weekend. Pete's is a good tip, I'm going to try that.

 

One tip I did pick up from the toyota manual, and of possible relevance to you, is that with the engine turned off and the system sealed you can test the master cylinder by pumping on the pedal a few times. When the pedal goes firm and you apply constant pressure to it for 15 secs or more there should be no movement. (thankfully mine is exactly like this) If there is movement that would show there is either a break in the pipe, or the master cylinder is knackered. It's logical if you think about it.

 

Also there was refrence to bleeding the master cylinder first if you have done any work on it before bleeding the rest. It did not, however, tell you HOW to do this..

 

The only things on mine I think could give soft feel are trapped air or a flexible line has been compromised allowing it to swell.

 

I will bleed again with a mate whilst running as well as off, just to make sure it cleans any crap out of the abs.

 

I also have half a mind to take the calipers off and bleed them as I rotate; so I can try and get any air pockets out. They fill from one side, connect to the other via a pipe, and I'm not 100% convinced that they will clear trapped air when they sit on their mounts.

 

A bleeding faq would be useful...

[SupraAyf]

Do we have a 'how to bleed brakes guide' here, if not i could always do one?? Mods?

 

That would be a good idea mate. It would also be ideal if we had a 'how to do' section on all service requirements.

[colsoop]

I use a good guide from here for bleeding the brakes:

 

CLICK ME

[JustGav]

Anyone know the part number for the MC service kit for an N/A 94 J-spec with ABS, just in case I need it?

 

Cheers

 

Any chance of an engine bay shot... 94 NA with ABS must be some unique.. interested to see how they have done it.

[ukApache]

Heres the pics of my engine bay. I've also taken a pic of what I believe is the ABS unit and the master cylinder as its off the car at the mo.

 

I've still got problems with the brakes though I re-bled them as described above but still the pedal touches to the floor and the brakes hardly work at all. I took off the master cylinder and had a look at the seals (well the only ones I could get to by removing the cir-clip) and they appear to be fine?

 

I have however noticed that when I push the piston in on the master cylinder brake fluid only squirts out of one of the holes (the one closest to the booster), is this normal?? Also while I got the MC off is there any way to test that the brake booster/servo is working correctly?

 

Cheers

[ukApache]

Bump

[dan4]

get it back together and clamp all 4 flexi hoses to the calipers, if you pedal goes hard then the air is in on of the calipers and its a case of removing the clamps one by one until you find the culprit. If the pedal stays soft you problem is closer to the reservoir

[ukApache]

get it back together and clamp all 4 flexi hoses to the calipers, if you pedal goes hard then the air is in on of the calipers and its a case of removing the clamps one by one until you find the culprit. If the pedal stays soft you problem is closer to the reservoir

 

Thanks for the advice

 

Only problem is I forgot to mention that I have SS brake lines so I cant clamp them Any way around this?

 

Cheers.

[ukApache]

sorry to keep posting about this problem but I am making no progress with it and dont know what else to do.

 

Things I have done so far:

 

- Serviced the calipers (new seals etc.)

- New SS brake lines

- Replaced master cylinder

- Bled brakes with engine off, on, using a 1 man bleeder kit & again several times with a mate

 

There is no fluid leaking anywhere Nothing seems to be blocked either as the fluid flows easily out of all the calipers when bleeding.

 

Process of elimination points to air trapped in the system I just cant seem to get it out.

 

If anyone has anymore suggestions I would be really grateful to hear them.

 

Thanks.

[Mike B]

If you turn you engine off, pump the brake pedal a few times is it holding pressure on thr pedal, or is it slowly sinking to the floor?

 

sounds like you may need to speak to a brake secialist.

[ukApache]

If you turn you engine off, pump the brake pedal a few times is it holding pressure on thr pedal, or is it slowly sinking to the floor?

 

if I pump it 7-8 times then it will hold. If I then let it go and wait for ~10 secs and then pump again it goes to the floor.

 

Cheers.

[merckx]

From the manual:

 

If the master cylinder has been disassembled or if the reservoir becomes empty, bleed the air from the master cylinder.

 

(a) Disconnect the brake lines from the master cylinder.

 

(b) Slowly depress the brake pedal and hold it.

 

© Block off the outer holes with your fingers, and release the brake pedal.

 

(d) Repeat (b) and © 3 or 4 times.

[dan4]

pressure the reservoir with 2bar pressure and try to bleed then? MC might not be picking up the fluid?

[ukApache]

From the manual:

 

If the master cylinder has been disassembled or if the reservoir becomes empty, bleed the air from the master cylinder.

 

(a) Disconnect the brake lines from the master cylinder.

 

(b) Slowly depress the brake pedal and hold it.

 

© Block off the outer holes with your fingers, and release the brake pedal.

 

(d) Repeat (b) and © 3 or 4 times.

 

Thanks

 

Although I did bench bleed the MC before I put it on

 

pressure the reservoir with 2bar pressure and try to bleed then? MC might not be picking up the fluid?

 

I was thinking of trying this but then I thought if the fluid is able to flow freely out the caliper the MC must be picking up fluid (please correct me if Im wrong on that)

 

Is this what you mean though?:

 

Thanks.