refurbing rear brake calipers

[Iaitoo]

The rubber hood thingy on one of the sliders doesnt sit on it and has a hole in it. The slider on the big thing in the middle that winds in/out, also seems to have a small hole in it. So I guess I have to refurbish it?

Is one of these kits ok? http://www.ebay.com/itm/Rear-Brake-Calip...SwwE5WaJM4

Is it hard?

[Eeyore]

ive never refurbished rear or front callipers. If someone has a guide or can do one that would be fantastic.

[zx_volcane]

They are an absolute arse, i fabbed up a tool to help compress the spring washers in the handbrake mech, but was still a nightmare. I swore at them for a good day.

There is little point just putting new rubber boots on ....

[Iaitoo]

They are an absolute arse, i fabbed up a tool to help compress the spring washers in the handbrake mech, but was still a nightmare. I swore at them for a good day.

There is little point just putting new rubber boots on ....

Language barrier here. It is no point putting new rubber on? Won't it leak brake fluid?

[zx_volcane]

the rubber boots just protect - so if split then likely to have corrosion on the piston and the sliders ...

[Iaitoo]

No corrosion yet, and it's just on one side. The other side actually had a pretty brown bolt. But is it ok as long as everything moves?
You think its better to get new calipers, because of possible corrosion then?

[zx_volcane]

I would buy recon rather than do it myself if I had to go through this again.

[pug306driver]

The slide pin o rings and gaiters are  relatively easy to do.

Is the hydraulic piston ( bendix caliper ) that is wound back in to un adjust so you can fit new pads, free, or very stiff??

If the piston is stiff, it can be "exercised" to free it off a bit, but an overhaul is the real answer. I have not had one of these calipers apart, but it can be done.

Had to replace rear flexy brake pipes very recently so soaked nipples and unions in penetrating fluid, they came out easy thank god, unlike the front calipers ( bosch ).

The hydraulic piston boot is relatively easy to replace.  Got parts from Bigg Redd, mail order.

I put a length of windscreen washer pipe on the nipples and filled with penetrating fluid and got on with the front brakes, giving time for the rears to soak. A small drill was used to clean the nipple hole of crap first. A hot air gun is handy but protect the rubbers.

With the handbake cable off the caliper lever ( no real need to remove the cable completley from the caliper, yet! ) , the handbake caliper lever can be used to "pump" the hydraulic piston out, but not too far, and then wind the piston back in, repeat till free.

Hope this helps.

I presume you will be changing the old brake fluid for new fluid.

Bigg Redd has on line tutorials that make it look sooooooo easy. The front calipers are easy, just take your time and absolute cleanliness, not done rear calipers, yet.

[Iaitoo]

Thanks for the write up. Got em lying on the table at the moment. It's on a beam I am going to put on the car

[Alan_M]

They're not too bad to rebuild. I rebuilt some for my VTS beam on the 306 (rebuilt beam deserved rebuilt calipers!). Trickiest part is the belville washers that you need to compress to push the lever pin back through but an old socket with slots suffices (there are other methods suggested on this forum).

I will warn you though, if you have to replace the pistons swapping over the handbrake mechanism inside is a TOTAL ballache.

I took a load of photos during the rebuild and I keep meaning to do a guide. Plus, if you get an old ZX Haynes, it tells you how to rebuild in there!

[pug306driver]

So, to remove the pistons to clean the corrosion on  the land between the hydraulic seal and the outer gaiter is a pita??

This area tends to corrode causing the piston to be stiff.

There is an exploded view in the 306 Haynes manual nut its not that clear, or clear how the caliper self adjust system works??

Since the piston is wound back in, suggests a thread system, possibly with a "flat " area on part of the thread????

  great that worked

The 4 bellows parts on the top right are the slide pin gaiters. on the extreme top left  is the hydraulic piston outer gaiter.
Next to that on the right is the main hydraulic seal.  the 2 o rings are for the slide pins. the slightly larger o ring is for the caliper hydraulics?? probably a hydraulic seal for the handbrake rod to the hand brake mechanical parts??  and the "eared o ring" is similar??? looks as if the "ear" covers a port, a one way valve????the rest is self explanatory.

Hope this helps with any language problem as we now have the same hymn sheet.

[Alan_M]

Yes, the handbrake mechanism is threaded. It operates via the plunger with a cam on the handbrake lever. Give me minute and I'll get some photos up.

[pug306driver]

brill!!!!!

[Alan_M]

Apologies for the pics, they're a bit blurry. Accidently go grease on the phone lens, took me ages to figure out why! Thought the phone camera was shagged.

You can see the threaded part of the plunger on this photo, piston removed.

http://s1153.photobucket.com/user/Alan_M77/media/IMAG01631_zps68wdnkux.jpg.htm

My slotted socket with a g-clamp to remove the lever from the plunger (compressing belville washers).

http://s1153.photobucket.com/user/Alan_M77/media/IMAG01611_zpsfie7lp9u.jpg.html

Lever, cam and retaining clip removed.

http://s1153.photobucket.com/user/Alan_M...s.jpg.html

Plunger and washers removed.

http://s1153.photobucket.com/user/Alan_M...s.jpg.html

All cleaned up and ready to go back together.

http://s1153.photobucket.com/user/Alan_M...h.jpg.html

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So, to remove the pistons to clean the corrosion on  the land between the hydraulic seal and the outer gaiter is a pita??

This area tends to corrode causing the piston to be stiff.

There is an exploded view in the 306 Haynes manual nut its not that clear, or clear how the caliper self adjust system works??

Since the piston is wound back in, suggests a thread system, possibly with a "flat " area on part of the thread????

  great that worked

The 4 bellows parts on the top right are the slide pin gaiters. on the extreme top left  is the hydraulic piston outer gaiter.
Next to that on the right is the main hydraulic seal.  the 2 o rings are for the slide pins. the slightly larger o ring is for the caliper hydraulics?? probably a hydraulic seal for the handbrake rod to the hand brake mechanical parts??  and the "eared o ring" is similar??? looks as if the "ear" covers a port, a one way valve????the rest is self explanatory.

Hope this helps with any language problem as we now have the same hymn sheet.

The O ring next to the dust cover is for the handbrake plunger. The O ring with 'ears' I used for the handbrake lever. If you look at the dustcover, one end is blind, the other is open. I slid the ear'd o ring on here, there are little grooves in the open end of the lever hole of the dust cover.

[pug306driver]

Thanks for the pictures, a little wiser now, and the struts, look at all that crap in the manifold!!

[Frosty]

I was thinking about refurbing the rear calipers on my dt but ended up buying some freshly refurbed 1s off a mate who got them from the scrap yard

[mattbarker32]

Did these the on mine the end of summer like people have said can be a pain. mainly compressing the washers to allow the removal of the shimes inside. Which allows the piston to be released. Would also check the slides/ carriers as if the seals have gone on there the pit really bad and may need just a clean or replaced. Recommend getting some castor grease and applying it to the piston before you slide it is back together and put some on the carriers as well and once back together get some moly grease (cv grease) and pack the main cover full of it will stop any water getting in. O and dont for get to check the hand brake pin for wear. It is one of the main things to cause handbrake fail as it wears and does not apply full pressure on it.

[Iaitoo]

Mainly the rubbers on the sliders that have gone. So I guess I'll order a couple of kits, and do those first. And see how it goes

[pug306driver]

yeah that's what i did to ours, still got the hydraulics seals. you have manual and know the slide pin torque?

lube the pad slider and the pad ears, but don't get any on the pad friction material and or discs.  if the small pad slider pin is knackered, i used a split pin the correct diameter and cut it short, just long enough to do the job, and splayed the open ends.

resulted in really good handbrake for mot test a few days ago.

red rubber grease is in big red kit from memory.

you know where the handbrake cable adjustment is??