Hey guys, my daughters car a TJ Solara is causing me issues once again.

Last week she called me up and told me she had brake issues, I went down and had a look and sure enough the right front caliper was not letting go, I removed it and found it was seized, I sourced a s/h one from a wreckers and also replaced the flex hose as a precaution, I drove the car afterwards and all seemed fine, but just now she called me up stating it has the same issue once again.

Is there something I'm missing here?, the car has ABS and my thoughts are that the module is not allowing fluid back into the master cylinder....and on that note bleeding the right front was a nightmare, I could only bleed it via holding the pedal down while the car was not running and then starting it and using the vacuum to help push the fluid through...something is not right that's for sure.

Please if someone has had this issue before can you please offer a solution?.

Thank you once again.

Terry.

Did you lube the slide pins?

Enough free play in the brake pedal?
There is a pressure relief port that is uncovered when the pedal is released, so there is no residual pressure in the lines. If there is insufficient free play, this port may not be uncovered. Also, accumulated rubber debris may be blocking the port.

Pump the brakes a few times, then loosen the bleed screw. If fluid squirts out, you know you have residual pressure.
Master cylinder should be cleaned out in that case, remove the old fluid and replace with fresh, try brakes again.
If that doesn't work, take off and dismantle for a proper clean.

Release pins were lubed prior to replacing the caliper, there was no residual pressure, the pedal is hard from the outset, but spongy if left for a little while.

I did the usual pump ten times and then open the nipple but very little to nothing came out, this is why I did the 'hold the pedal down, then start the engine' to assist in bleeding, this worked and all air
was removed, and as mentioned I test drove the car and it seemed fine, I tested on both gravel and bitumen and the bias was perfect, but now she says the right side is turning the rotor blue and it
gets much hotter then the left side. She also says that the car is vibrating through the wheel at speed, something it did prior to me changing the caliper.

I am at a loss here, my thoughts are that if the caliper was not releasing it would pull to the right, which it does not, unless it is grabbing just enough to continue to get the rotor hot and nothing more.

I also thought that for whatever reason the return valve for the fluid may not be working correctly causing this problem, but I am unfamiliar with the Magna braking system and assume it is like most
others, where the fluid from both front brakes is returned via a single valve, meaning if it were problematic it would cause both sides to have issues and not just the right side, this is what has me thinking
that maybe the issue is with the ABS module, because the front brakes should be on a single circuit (correct me if I'm wrong) and if not then perhaps there is some form of blockage or faulty return valve in the ABS unit....I'm stumped :/

The second hand caliper - did you pull it apart and clean it out?

Probably seized up piston due to grot or rust.
The initial problem with bleeding it is a sure hint that the piston doesn't want to move easily.

I don't know where you got that caliper from, if it is from a wreckers, never assume anything you buy there is "as new" condition wise.

In reply to your question, yes the caliper was stripped as far as one can, the release pins were removed and lubed, dust covers checked and were fine, no signs of debris or damage to the pins themselves.
Piston was pushed back to fit new pads etc, so not seized at all.

The thing is that pumping the brakes ten time and then opening the nipple produced little to nothing, yet the brakes clearly had air in them.
I should point out at this stage that because I live so far away from my daughter 360kms, she took it to a so called mechanic who called her after looking at it and told her "I can't bleed the brakes, come and pick it up, it's still safe to drive".
Upon inspecting his work he had left the flex hose loose and fluid was literally leaking from the hose at the copper washers...shonky right?....anyway the car clearly was full of air and I could not bleed it either, I then recalled my old trade school teacher
telling me how to clear blocked bleed nipples, and that was the method I explained earlier, ie: no pumping, just once hard on the pedal, then start the car and let the vacuum do the work, and this is how I had to bleed the system.

So in summing up the calipers are fine, it's something beyond them, and if you MadMax can't help me I feel it's beyond reproach, and something I will have to figure out for myself, using the tried and true method of process of elimination, the problem with that
is I have to buy firstly the MC and if that doesn't fix it then the ABS unit...all of which comes out of my pocket because my daughter is not currently working......sigh...still stumped.

I should probably add that the left side was very easy to bleed and behaved exactly as one would expect, the problem is isolated to the right side only.

You need to isolate the problem to either the caliper or upstream of it. You should be able to open the bleed nipple and with the engine off and no pedal pressure the fluid should slowly trickle out. If not, I would remove the brake line from the caliper and check that: 1) fluid flows freely from the line, and 2) that with the nipple open you can blow air freely through the caliper piston (after the fluid that's in it blows through of course). This should indicate whether it's the caliper that's cactus or it's not getting fluid.

If the caliper checks out the problem could be a dicky master cylinder or a blocked brake line. The master cylinder is a dual type, with two separate co-axial plungers. One operates the front left and rear right brakes, the other operates the front right and rear left brakes, and they are capable of operating independently (that's the point, if one circuit fails you still have one front and one rear brake). If it is the MC the problem should also be apparent on the diagonally opposite side of the car, ie. the pass-side rear brake should also be hard to bleed (though the disc might not be getting hot). If the problem is only with the front right caliper and the caliper itself checks out I'd suspect a blocked proportioning valve or brake line, otherwise I'd be getting the MC looked at.

Piston was pushed back to fit new pads etc, so not seized at all.
..sigh...still stumped.

lol You have cleaned up the caliper as best as you can, except for the most important part. The piston needs to be a smooth sliding fit in the bore, just pushing the piston back tells you nothing.

With a normally working caliper, the outward movement of the piston distorts the seal. Release the pedal, and the distorted seal pulls the piston back. This force is smaller than the force you used to push the piston back in by hand. In fact it only take a little bit of grot or rust inside the bore to stop the piston from retracting correctly.

Pop the piston out, clean up the bore and piston, reassemble, all fixed.
If you don't want to do this yourself, see a brake shop. They will tidy it up to as new condition.

I've bought older Magnas in the past, both TSs I've bought were near or over 200,000 km.
For each, I pulled the pistons out of all the calipers, and cleaned them up. Lots of rubber wear material and a few rust spots in there. Brakes worked better and smoother afterwards.

Surely even if the piston was jammed it should still be possible to bleed it? For fluid to not trickle or pump through an open nipple there'd have to be a blockage somewhere or the master cylinder isn't pushing fluid or allowing it to return. I agree that it's always worthwhile dismantling and reconditioning with new seals a caliper before fitting, I don't like unknowns when it come to throwing out the anchor.

Surely even if the piston was jammed it should still be possible to bleed it? For fluid to not trickle or pump through an open nipple there'd have to be a blockage somewhere or the master cylinder isn't pushing fluid or allowing it to return. I agree that it's always worthwhile dismantling and reconditioning with new seals a caliper before fitting, I don't like unknowns when it come to throwing out the anchor.

This is my point entirely, opening the bleed nipple should allow fluid through, however it does not. No amount of pumping the pedal nor force will coerce the fluid from the nipple, as mentioned the only way I could do it was to stamp on the brakes and then start the car,
but even then it did not want to squirt out, rather it was more like a strained piss, even with the pads not touching the rotor the piston didn't want to move, it moved slightly but not enough to make contact. It was only after the coerced bleeding that the brakes worked.
They tested fine when I drove it but as I say, my daughter is complaining of the exact same issue.

If it is the MC the problem should also be apparent on the diagonally opposite side of the car, ie. the pass-side rear brake should also be hard to bleed (though the disc might not be getting hot). If the problem is only with the front right caliper and the caliper itself checks out I'd suspect a blocked proportioning valve or brake line, otherwise I'd be getting the MC looked at.

Sorry to say, but this is not how a brake circuit works, the front and rear are separate, having them diagonally opposed would make the car extremely dangerous. Having one front and one rear working would kill far more then it would save, stomping on the brakes with that system would reef the wheel right out of your hands. The design is if one system fails ie: the front the rear still works and vise versa.

Sorry to say, but this is not how a brake circuit works, the front and rear are separate, having them diagonally opposed would make the car extremely dangerous. Having one front and one rear working would kill far more then it would save, stomping on the brakes with that system would reef the wheel right out of your hands. The design is if one system fails ie: the front the rear still works and vise versa.

Not according to the manual. It clearly indicates a diagonal setup, with one plunger in the MC operating right-front and left-rear, the other left-front and right-rear. The rationale is that you will always have at least one front brake. With a front/back setup a single failure in the MC (such as the one I suspect you have) or a single leaky line could potentially leave you with no front brakes at all. Diagonal braking systems are quite common, though there are a number of different setups. Simple test is to see if you can bleed the left-rear brake normally.

This is my point entirely, opening the bleed nipple should allow fluid through, however it does not. No amount of pumping the pedal nor force will coerce the fluid from the nipple, as mentioned the only way I could do it was to stamp on the brakes and then start the car,
but even then it did not want to squirt out, rather it was more like a strained piss, even with the pads not touching the rotor the piston didn't want to move, it moved slightly but not enough to make contact. It was only after the coerced bleeding that the brakes worked.
They tested fine when I drove it but as I say, my daughter is complaining of the exact same issue.

This is why I suspect one of the plungers in your master cylinder is stuck, especially since the problem remained after swapping out the caliper. A stuck plunger will not push much fluid and won't allow it to return, which kinda sounds like what you've got.

This would be true if it wasn't for the fact that the left side bled just fine.....I'm really stumped here, but the more I think about it the more I'm thinking it's the ABS module....I wonder if it would throw up a code??... I should have taken my OBDII down with me....I never even thought to pack it...sheesh.

This would be true if it wasn't for the fact that the left side bled just fine.....I'm really stumped here, but the more I think about it the more I'm thinking it's the ABS module....I wonder if it would throw up a code??... I should have taken my OBDII down with me....I never even thought to pack it...sheesh.

Left front or left rear? Left front is driven by the other plunger from right front.

Ahhh it will throw up code 43....I just checked the manual.....oh well looks like another 700km round trip for dad :(

Sorry to say, but this is not how a brake circuit works, the front and rear are separate, having them diagonally opposed would make the car extremely dangerous. Having one front and one rear working would kill far more then it would save, stomping on the brakes with that system would reef the wheel right out of your hands. The design is if one system fails ie: the front the rear still works and vise versa.

actually ensoniq5 is right. alot of modern cars work on a diagonal setup. they clearly say so in the owners manual that comes with the vehicle. as for 'reefing' the steering wheel right out of your hands, thats your speculation. why would car manufacturers go with a diagonal setup if this were to happen.
either try a rebuilt caliper or a rebuilt MC and check the line from MC to the caliper in question is not damaged. second hand stuff from wreckers is not reliable especially if sitting there for a long time.
good luck and once you find out the problem, letting others know on here is a big help especially if something similar happens to a fellow magna owner

once you find out the problem, letting others know on here is a big help especially if something similar happens to a fellow magna owner

Already has, to me.
Usually pulling the piston out of the calliper, cleaning the bore and piston thoroughly and cleaning out the rust/debris from the bleeder valve and port fixes the problem.
I've only had those symptoms 2 or 3 times - a dragging calliper that would not bleed properly - and fixed it this way, but what would I know? lol

Nice to see though, that someone else recognises a part from the wreckers may be in the same or worse condition than the part you are replacing. :nuts:

Nice to see though, that someone else recognises a part from the wreckers may be in the same or worse condition than the part you are replacing. :nuts:

It goes without saying that any brake part from a wreckers should be fully stripped, cleaned and kitted before fitting, daft not to do so. I took post #5 in this thread to mean that had been done, hence looking 'upstream' of the caliper for the faulty component. It would take 10 minutes to isolate the faulty part, the OP has mentioned that he has the manual so should be able to work it out.

Read the OP's posts again and you will see he hasn't actually popped the piston out to clean and examine it.
All he has done is changed one gunked up calliper on the car with another gunked up calliper from the wreckers.

Not my car, so should I worry? Nope!

PS I've bought two TSs at different times in the past, both at or over 200,000 km. Both showed dragging callipers, so all 4 corners on both cars had their pistons popped out of the callipers, lots of rubber wear material in them from the rubber brake components, one piston showed some rust but it cleaned up ok with a light wet and dry sand. Brakes felt great afterwards, probably saved on pad wear and petrol too.

Didn't need to re-kit any of them, by the way.

Sounds like a blocked hose somewhere back toward the Master Cylinder or the cylinder itself is dicky, as Ensoniq suggests. You might have to bite the bullet and spend the money on a brake specialist.

Read the OP's posts again and you will see he hasn't actually popped the piston out to clean and examine it.
All he has done is changed one gunked up calliper on the car with another gunked up calliper from the wreckers.

Not my car, so should I worry? Nope!

PS I've bought two TSs at different times in the past, both at or over 200,000 km. Both showed dragging callipers, so all 4 corners on both cars had their pistons popped out of the callipers, lots of rubber wear material in them from the rubber brake components, one piston showed some rust but it cleaned up ok with a light wet and dry sand. Brakes felt great afterwards, probably saved on pad wear and petrol too.

Didn't need to re-kit any of them, by the way.

True, it doesn't look like the caliper was fully dismantled and could very well be gunked up. Simple check is to remove the brake line. If fluid flows nicely and squirts with a bit of pedal then it's the caliper, if not, it ain't. My biggest concern on reading the thread back is the mechanic who couldn't bleed the brakes but said it wasn't a problem. WTF? Anything unusual with the brakes is surely a cause for concern.

Kitting is something I'd always do as a matter of course, if you've gone to the trouble to dismantle the caliper (and nearly lose a thumb in the process ;)) and clean everything up it just makes sense to me to fit new rubber bits. Maybe I'm just a pessimist!