GQ Brake Pistons

[Robo]

Yep they were super hot Im talking loose your finger print if you touch it hot. I wasnt resting my foot on the brake pedal Im too lazy to keep my foot up there when crusing the highway
see I was maby 10 minutes from home and I could here a squeel from the brakes so I would dab on the pedal and it would stop then a few ks it would do it again and that happened 5 or 6 times so had a look at home and found all was cooking.

I pulled the other side caliper off today and I would say the piston is pushed out as far as the rubber boot will extend and I cant push it back in by hand...is that normal?
Also opened front caliper on one side and that piston is also unmovable..Ill post up more pics tomorrow.

Hi mate, not accusing anyone of any thing just trying to help find a cause for problem, I work on the Rd for buck and see brake light flashing now and then.
From what you write pads and discs past usable spec and due to be replaced, no worries cheap.
slotted rotors, pads, cal kits and fluid approx $300 diy these days, just did mine before chrissy to easy.
Pistons have kicked a little sideways they have ext a long way out, this should be nothing to worry about once rebuilt with new pads etc.
tap carefully to straighten up and it should come out, be careful not to drop it, compressed air and a block of wood to trap it inside cal assembly instead of it flying out breaking fingers ,gently, slowly does it.

[Robo]

this is a messy job air to assist piston out,cover, maybe safety glasses you don't want fluid in ya eyes

[Silver]

the rubber bits are disposable once damaged in any fashion.
cleaning product will stuff em completely forget it.
taking chances with your or others lives for way less than $100 dollars !!!.
don't do it bud.
Happy motoring, not condolences.

The only rubber bits that I cleaned with kero were the slider boots. I would have bought replacements had they been available at the time.

The calipers were fine -no need to do anything with the pistons, so the 'Q got new rotors and pads, and nice slippery slide bolts again.

This was all back in Jan 2011 when I did the front swivel hubs - and that is when I glued the splits. They are still fine, and I check them when under the 'Q.

I am reasonably comfortable taking this approach with the slider boots, Robo. If the slider boots split again they'll let moisture and crud into the slider bolts, which I will pick up while under there for some other reason. As you know they won't cause a major leak of fluid for example.

[Robo]

The only rubber bits that I cleaned with kero were the slider boots. I would have bought replacements had they been available at the time.

The calipers were fine -no need to do anything with the pistons, so the 'Q got new rotors and pads, and nice slippery slide bolts again.

This was all back in Jan 2011 when I did the front swivel hubs - and that is when I glued the splits. They are still fine, and I check them when under the 'Q.

I am reasonably comfortable taking this approach with the slider boots, Robo. If the slider boots split again they'll let moisture and crud into the slider bolts, which I will pick up while under there for some other reason. As you know they won't cause a major leak of fluid for example.

Mate do what ever turns ya on.
No need to make it personal.
This is a help thread isn't it.
Our buddy is about to try something it appears for the first time that is critical life threatening work on his 4x4 .Its more involved work than preformed by yourself, so requires more attention to detail. He may of accidently sprayed cleaner onto components without reading can first and then things would have gone sideways for him.
Simply pointing out brake cleaners and properly every maintance manual ever written, something like not to be used on rubber brake components, so our mate can decide on an approach for himself that's all.
Cheers

[Bigrig]

Call me dumb, but I've sort of missed the point on the 'dangerous' part in all this ...

Please explain?? (quote Pauline Hansen!! lol).

I'm sure both you lads are heading down a certain path and sort of see no head butting at all truth be told (Silver isn't the head butting kind of guy I can assure you).

I'm more than interested (genuinely) in what you're getting at Robo - break it down for a dumb @ss like me and there'll be no room for interpretation (forum speak is a pain sometimes as no body language, tone etc comes through so people can think someone's having a swipe when in fact they are truly just on a different train of thought).

Thanks in advance!!

[Rip'n'Shred]

The dangerous part comes from the fact they are brakes and they play a critical role in doing stopping your 3t truck.

I am ex mechanic and have done many caliper rebuilds in the past. I strongly recommend you either take the calipers or the whole vehicle to a brake expert if you are even slightly not confident in what you are doing with them. Lives depend on your brakes.

Maybe, if your confident enough, get the calipers done professionally and install yourself with new fluid throughout, new pads and as said before regrease your wheel bearings yourself. Get the brake guys to check your rotors too.

And for gods sake, do it in pairs! Both front! Essential!

Could be expensive in the end, but worth every penny.

[Silver]

Thanks BigRig and Robo,

I certainly meant no offence Robo, and if I offended, I apologise.

In the meantime, I think Robo and I are singing from the same song sheet, except maybe whether brake cleaner spray or spray degreaser should not be used on rubber brake components. I know that kero is no good for them from personal experience.

We have in common:

Brakes are a critical system with severe consequences if things go wrong.

We noted with interest that some on this thread have used other kinds of grease in contact with rubber brake components, whereas Robo and I were both 'brought up' with the view that it is rubber grease only (or clean new brake fluid) that can be used to lubricate rubber brake components. The experience of the others seems to be different to what Robo and I were taught.

To alert Trolatron to a mistake I had made, I posted that I had incorrectly washed the slider boots in kero which caused them to swell. They subsequently returned to normal si2e. Because the pads on Silver were so worn, the boots were extended and thus split. I was unable to buy replacement boots, so superglued the splits - which has worked for a year + probably because the boots are compressed due to new pads. Both Robo and I agree it would have been better to get new boots - Robo might go so far as to say that this is essential. In my case the consequence of a boot failure is that the caliper would become sticky and wear the pad/s prematurely. I am monitoring same, and all is good so far.

I pointed out that unlike Trolatron, I did not have to work on the piston seals etc - the point being that if I had washed those in kero, and they had grown and shrunk, I would have binned them regardless as I see the consequence of failure as different to boot failure.

Robo gave some information in relation to the benefits and dangers of using compressed air to shift stuck pistons.

All the best with your repairs Trolatron - and don't forget another option is to take the whole caliper to a professional and get them to rebuild it - that's what we did with Bob's caliper, which had a torn piston seal after it was pushed back.

Rick

[Robo]

The dangerous part comes from the fact they are brakes and they play a critical role in doing stopping your 3t truck.

I am ex mechanic and have done many caliper rebuilds in the past. I strongly recommend you either take the calipers or the whole vehicle to a brake expert if you are even slightly not confident in what you are doing with them. Lives depend on your brakes.

Maybe, if your confident enough, get the calipers done professionally and install yourself with new fluid throughout, new pads and as said before regrease your wheel bearings yourself. Get the brake guys to check your rotors too.

And for gods sake, do it in pairs! Both front! Essential!

Could be expensive in the end, but worth every penny.

Now I read your post I think I may/should of written similar, but our mate had em already on the bench in bits.

[Trolatron]

Thanks for all your replies guys it's much apreciated, I didnt get to play in the shed today like I had planned, Ill take them into the brake guys tomorrow for inspectoin and see what they say hopefully all is ok and all they need is new seal kits put threw them and new rear pads as the front ones are only half worn ( the rear are down to 1.5mm ) .
I know its hard for you guys to diagnose whats going on with them from behind a computer screen and if you could only pick them up and see them in person you could diagnose problems much easyer (and my notes arn't much chop to go on lol ) but its great to get info of this forum as you guys have been there and done that and you know your Patrols where as most mechanical places know general stuff about all cars and 4bys but not all the tricks and traits from an owners day to day living with them like you lot do and it gives us little guys the confidence to have a go at fixing out own trucks and learn how they work or why they dont work

Enough dribble and spelling mistakes from me for now.. Ill post back on how I get on.

Cheers Ray

[Trolatron]

Ok guys I made a little video to show progress so far . Should have done it first off at start of thread ill try it next time.