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[thorna]

Hi Everyone;
I'm going through a vehicle maintenance time:
Latest one is seized callipers; usually at convenient times such as the M5 South on Bank holiday Friday.
On the plus side I'm getting good at driving with em sticking on!

So I need to refurb the front callipers; inner bores are rusty etc & piston is sticking out.
I think theres a rebuild kit from L'House available? Anyone know how much, alsro read somewhere about stainless pistons as an upgrade.
How tricky is it to do at home (incl honing the bore), I have the full tech manual & I'm ok at stuff like this but do have more skilled friends who can help if required.

Anyone know of a local (West Mids) companies that can refurb them?

I'm tight on time; needs to be all done by Friday PM.

Cheers

[Ian Houghton]

I bought a piston and seal kit from ebay £17.95 plus postage, it didn't include the sliders which if the boots arn't split they can be cleaned up and greased.

If you decide to fit a new pistion and seal kit after fitting the piston put a small amount of brake fluid on before you put the dust seal on, this help to keep the outerside of the piston lubed with out doing th seal any damage.

[MOCAJ]

inner bores are rusty etc & piston is sticking out.
Cheers

if the inner bores are rusty and pitted you will need new calipers as new seals wont do the biz unless you can hone it out and the original seal will fill the bigger diameter

[wazza]

£13.90 + vat + postage from light house. ive just bout some a week ago. all you get is the piston, seal an rubber boot.

give the boars a clean up with emery if theyre not to bad! just make sure you give it a good clean out, remember its the new piston sliding over the fixed place seal not the boar an for the movement you wont score/ damage the piston where the seal is going to be.

[keegantj]

Look on ebay.com and type in Jeep calipers. There is a chap called Bigfoot that sells a brand new pair for £55 inc delivery to the UK. I have bought 2 pairs so far and they are delivered in @ 5 working days, plus there is no vat or import duty!!

[thorna]

Cheers guys; you've given me all the info I need:
Took the calipers off last night; one of the pistons has a chunk missing.
Down to 3 options
1. local co. will refurb them in 24hrs for £100+
2. lighthouse kit for £20 & do it myself
3. Buy new ones (cheers KeeganTJ for the link; these are an absolute bargain!)

Option 3 is best but can't be done in time, so may go with the lighthouse kit & have a go myself! Can always buy a set off eblag & fit later.
while getting them done by a company is min. hassle its also expensive for what are basic units!

Might sand blast the callipers as well.

[JamesH]

I've got a pair that I no longer require (I have upgraded my front brakes)They have brand new brake pads fitted and one has a new piston kit fitted. I only drove about 5miles as a test drive before the Jeep got all new modifications and they were no longer needed.

If they would be any use to you I could send them to you for the cost of postage +£30 (new pads were £25)

[thorna]

Hey James; I'd have taken you up on those brakes you have for sale; if I hadn't already started the rebuild & ordered all the kit!

Didn't make my Friday deadline either   so no beach for me!

Anybody got any tricks for inserting the new dust boot into the caliper bore. Really struggling with this (even to do 1) despite making up a 'cup' fixture to go over the rim of the boot to push it home?

The bore was in great condition & I cleaned them up a treat; however the new piston doesn't run easily in the seal; it needs a lot of force to move it (eg hammer & block); should I be concerned?

[PtP]

should I be concerned?

Yes!

Make sure the piston is moving freely in the cylinder before you put the new seal in the cylinder. Also rotate it to make sure it's not binding on any rust spots around the top rim of the cylinder. I do recall though that once the seal was used it did become tight to move by hand.

I did a write-up on this a while ago - here it is:

Well, I thought I would tackle the job and I’m glad I did so far as the job has been very easy.

I thought I would get away with just stripping the calliper, cleaning the rust and crud and rebuilding it!

Not quite as straight forward as I first thought.

I stripped the piston out and discovered there was a ridge of rust deposited around the edge and I also discovered that the piston is not made from steel, but some sort of resin material / Bakelite. Anyway, a very light rub on some 600 grit wet and dry and the rust deposit was removed.

This photo shows the piston after I removed the rust.



Next I realised the rust had come from the ring of metal by the seal in the casting.



So a gentle rub with the 600 paper and all the rust was removed.



In the process of rubbing this area of the cylinder, I realised that there must be a split in the outer seal to have let all the water in which had caused this to rust up. Sure enough, here is the split.



A quick call to Lighthouse who have the service kits in stock and I’m now waiting for the post in the morning.

Knowing that there is a new piston on its way I removed the internal seal from the cylinder and inserted the piston and to my surprise it got stuck despite having removed all the crud and rust! In some positions it was working, but if I rotated it a few degrees one way or another it became stuck again. I very gently rubbed the piston again on the 600 paper and now it’s a perfect fit! I will use the new piston though. But it just goes to show, what you thing is clean and back to size is not! I also rotated the piston in the cylinder after this second sanding and there was no sign of any interference, just a good close and snug fit.

The service kits include the piston, inner seal and outer seal are only £13.90 plus VAT and p&p. I’ve ordered 2 sets!

[thorna]

Thanks ptp, great write up

My new pistons run ok in the bore its just when the seal is in they become real tough to shift.

How did you install the new dust boot?
Is just not happening despite using a 'jig'as per the tech manual; I've just wrecked a boot!
I did a full strip down, clean up & repaint of the ironwork so I think the surface is in good order etc.

[PtP]

How did you install the new dust boot?

I recall it was just a gentle push fit with a very gentle tap with a hammer just to make sure they were tapped all the way home. No real force was used. I hope this helps.

[demonicwillow]

I believe the pistons are ceramic!!

[Bubba]

good old cjs are steel

[JamesH]

They are a bakelite material, don't hit too hard with anything  

[neilh]

How did you install the new dust boot?
Is just not happening despite using a 'jig'as per the tech manual; I've just wrecked a boot!
I did a full strip down, clean up & repaint of the ironwork so I think the surface is in good order etc.

How did you install the new dust boot?

I recall it was just a gentle push fit with a very gentle tap with a hammer just to make sure they were tapped all the way home. No real force was used. I hope this helps.

Apologies for dragging up an old thread but has anyone found slight differences in the piston rebuild kits? I'm buggered if we can get the dust boot to sit properly, it's almost as though the dust boot is slightly too big. It certainly isn't going in with a gentle push fit! 

[Dave69]

they are a pain to fit but fir the boot first before inserting the piston

[neilh]

they are a pain to fit but fir the boot first before inserting the piston

Any tips? It's almost like the boot is too big 

[Dave69]

It will be a tight fit over the piston and a "loose fit" in the caliper. The piston then keeps the boot in place when assembled.

Thats why its a pain to fit, either you get it right first time or it seems to take forever.

Unfortunately no simple tricks or tips to install, just use brake fluid as a lubricant and keep trying

[thorna]

rebuild kit; It never worked for me or my trusted mechanic at the time.
Can only recommend chucking them over the hedge and buying new from ebay.com