After 'Cherryblossom' my 1990 XJS V12 finally got to the stage where I could drive her round the Garden, I was convinced that after a while the Callipers would ease off, as I put New ones on her 16 years ago (Service Exchange) before I laid her up.

But it looks as though I've been kidding myself as the Front Wheels are still fairly tight and I know what happened last time, the Brake Fluid started boiling and my 'Grey' Car nearly caught fire.

So I am going to put some New ones (Service Exchange) on regardless and while I know that I could buy a kit to repair them, to me it really isn't worth the hassle as if I get Service Exchange ones, then at least I'll know the jobs done right.

As changing a Set of Callipers can be 'interesting' if you have a problem getting those bolts undone.

The going rate for the Front ones, is about £130 each with a refund of £30 when you return the old units.

Though 3 years ago I was able to buy a pair of these for £60 after a £60 refund for the old units.

As you can imagine, I'm really starting to regret not buying another Spare Set at that price, so if anyone come across a deal in the (UK) please would you let me know.

 

OB,

As you probably know the part numbers for the calipers are AAU2102 & 2103. Fortunately there are plenty of people selling these as there are a number of remanufactured and reconditioned options. If you google around You can get them as cheap as £55 each + £20 exchange fee (www.cheapbrakecalipers.xo.uk). I guess you need to decide what quality you're looking for.

Hope that helps

Paul

 

According to their website they are remanufactured OEM calipers.

 

Are you not throwing the baby out with the bathwater? How do you know the calipers are the problem?

 

Hi Paul

Many Thanks

I knew I could rely on you to come up with something and it looks as though you have!

Thanks for your help.

 

Hi Steve

That's what I wanted isn't it?

Brand New ones would cost a Fortune.

 

Hi Mikey

When I Jack her up the Front Wheels are quite hard to turn, I know its not the Wheel Bearings but can you think of anything else it could be.

I know the Pads are binding but if it isn't a Calliper problem with the Pistons not going back, what else do you think it could be?

 

Could be a collapsed flex line. Could be the calipers binding on the pins. Could be the master cylinder not releasing. Maybe 4-5 other things I can't remember right now.

I'd remove the wheel and try to turn the hub. Open the bleeder and see if it gets easier to turn. If so, it's not the caliper.

Remove the caliper assy to see if the hub is easier to turn. If it's free, inspect the caliper for corrosion on the pins. See if the piston can be pushed back into the housing.

 

Hi Mikey

I did check the Pads a bit earlier on and I think they could be getting jammed on the pins just like you say but I am also planning to shave the Top and Bottom of the Metal Bit of the Pad, with an Angle Grinder and see if that makes any difference as they are sticking somewhere.

 

That's not how it should be tackled OB.

 

I've done it before on my Grey XJS and it worked a Treat.

We are only talking about a few Thou with a Sanding Wheel on my Grinder, I'm not intending to go hacking lumps off.

 

Hi Guys

The Front Wheels on my XJS V12 are binding on both sides, which appears to be caused by Stuck Calipers.

Although I put on New Ones 16 Years ago the Car was never used on the road after that.

So what's the best way to free them off?

Is it possible to do that, or would I have to buy a complete repair kit which would include New Pistons.

Ideally I would replace them, with rebuilt Service Exchange Units but the Price of those has gone right through the roof Circa £250 per pair.

And I cannot manage to get hold of the firm that does them for around half that price.

Does anyone have experience of how you rebuild them or can recommend a Video on YouTube.

 

The calipers are not too difficult.

They unbolt, just make note of where the Xover pipe goes.

Before you tear them apart use compressed air in the fluid inlet to blow the pistons out. I didn't and it was a little harder.

Once the pistons are out use a spike to remove the seal and discard.

Clean the calipers fully with brake cleaning fluid. I painted mine with silver caliper paint.

When re-assembling use copper grease on the piston seals.

First pic is my front calipers. I could not find the finished pic of the fronts but the second is the rears.

.

 

No external crossover on fronts but make sure you get the correct seal for the internal channel for reassembly.

 

OB, I'm assuming these are the same calipers so I've merged your two threads.

 

I'd remove them and see exactly what's stuck before anything else. If they're brand new and were stored with freash fluid in them they might just need a good cleaning.

 

Hi Warrjon

I didn't want to split them, as I've been told that's not a good idea but If I can get the Pistons out and find they are not pitted, then maybe a good clean and new seal kit would do it.

 

That sounds like a Plan

Thanks for your suggestion.

 

Baxtor, Warrjon
I have never been able to find a source for the seal between the two caliper halves. Where did you get yours from, please?
Greg

 

If memory serves me correctly I used an O ring bought from my local Auto parts store. It was a few years ago now.