1976 2200tc

[Tom W]

Slight change of plan.....

I'm thinking of leaving the callipers in place for the time being, and just removing the pads to see if the auto adjuster mechanism looks like it's doing it's thing. The callipers themselves look fairly new, with almost no surface corrosion, so hopefully everything inside will be OK. I need to replace the O rings on the calliper securing nuts, as they've split so I'll do that before tightening everything up.

I don't want to take too much apart that I don't understand yet, so will see where new pads and bleeding the brakes gets me.

 

[richarduk]

Slight change of plan.....

I'm thinking of leaving the callipers in place for the time being, and just removing the pads to see if the auto adjuster mechanism looks like it's doing it's thing. The callipers themselves look fairly new, with almost no surface corrosion, so hopefully everything inside will be OK. I need to replace the O rings on the calliper securing nuts, as they've split so I'll do that before tightening everything up.

I don't want to take too much apart that I don't understand yet, so will see where new pads and bleeding the brakes gets me.

Worth while giving it a go, would save a posible hipcups, the rears inner bits are a bit complicated. Took me a copule attempts to get them back correctly.

 

[DaveHerns]

You could take the caliper covers off - 2 nuts - and see if there is any fluid inside .If there is , you're in for a strip down

 

[harveyp6]

You could take the caliper covers off - 2 nuts - and see if there is any fluid inside .If there is , you're in for a strip down

No need to take the cover off, just slide a thin screwdriver between the caliper body and the rubber, if you get covered in fluid, it's leaking..........

 

[arthuy]

to check if the handbrake is working I cup my hand over the caliper and either operate the lever on the caliper or get someone to pull the handbrake on. Doing this you will feel some movement and with it on the pads should be tight against the disc. If you pull and push it there should be no free movement.

Common problem is that the pads have stuck. there is squared of pins which the inner pad slides on. this can rust up or be caked in dirt, also I have seen thin shims. these will prevent the inner pad sliding. .

The Cup ( the piston type thing that pushes the pad) also rusts up and will not adjust so when the pads wear the brakes become poor.

Since you have droped the diff make sure you correctly torque them before driving to avoid damage to the diff plate.

Colin

 

[richarduk]

Common problem is that the pads have stuck. there is squared of pins which the inner pad slides on. this can rust up or be caked in dirt, also I have seen thin shims. these will prevent the inner pad sliding.
Colin

That sounds a good bet for the symptoms you've have.

 

[Tom W]

I've not done any work on the car tonight, so no more progress to report, but hope to get some done tomorrow evening when I get in from work.

Regarding the rear brakes, I think things have become slightly seized with the car standing. From memory, when I first went to look at the car in Feb, the handbrake did work slightly.

Does anyone know the correct torque for the diff mounting bolts? I'm going to get some threadlock on them too.

It also looks like the pipe between the brake reservoir and master cylinder is leaking slightly where it joins the reservoir. I need to investigate further, as it could be a split in the reservoir.

Then it's on to sorting the exhaust. This looks like someone's really bodged it in the past. The mid and back boxes look standard, but the front pipe is a plain pipe that's been crudely welded in. The joints are butt welds, with weld only round the accessible bottom half of the joints, and the welding looks terrible. At the front, there's a flexi pipe that's been welded into the manifold, not bolted on. This means either a new manifold, or saw off the flexi pipe and grind the rest back out Hopefully the welding is so bad, it might just break off with a little persuasion :roll:

 

[Tom W]

More progress today

I've managed to remove all the pads. The inner pad on the nearside was stuck on the metal retaining plate. This could be the cause of some of my problems. The pads don't look too worn, probably about 4-5mm left, but probably worth fitting new anyway whilst it's all apart. I'll be cleaning up all these parts and rubbing down the corroded surfaces before reassembly. Is it worth using a bit of copper grease on everything during reassembly?

I've started removing the handbrake linkage too. Managed to get the split pin and clevis pin out on the nearside, but the off side is proving more reluctant. Next I can tackle those strange folded steel nuts on the forward ends of the callipers, and hopefully remove the callipers.

Sorry, no more pics yet, as the camera doesn't work very well in the dark in the under the car.

 

[richarduk]

Is it worth using a bit of copper grease on everything during reassembly?

100% yes. Glad you're starting to make progress. Just think how much that would have cost you at a guarage, they would have had that same problems and no Forum to help. I would say once you've done the rear brakes you're a fully fledged P6 owner. :wink:

 

[Tom W]

OK, starting to get stuck now.

I can't get the bolts out that hold the callipers in. I've removed the nuts from the back of the calliper on the pivot bolts, but I can't get the bolts out. I've tried tapping the end of the bolt to drift it out, but no luck. I don't want to hit anything too hard, in case I damage the end of the bolt.

I've removed the stop from the handbrake actuating quadrant, so now I can get a 24mm socket on the folded steel nut on the other end of the bolt, but this doesn't appear to turn. Again, I don't want to apply too much force in case things aren't supposed to come apart this way.

Any advice?

Thanks

 

[harveyp6]

You need to get the 15/16" AF bolt out from the front of the pivot, then with the nut on the back removed, (the one with the 2 "O" rings) then the pivot will come out towards the front of the car.

 

[Tom W]

You need to remove the funny looking bolt to get the pivot pins to slide out so you can remove the calipers. Good job you didn't tell me 30 years ago that it was impossible get a spanner on them, as I never would have been able to do any...........*




* You need to use a good quality 15/16" AF oe spanner.

The problem you will have now is that because you've dropped the diff it will be flopping about all over the place and you won't be able to get enough purchase on them to undo them.

Remove the clevis pins from the caliper quadrants, unhook the spring from the crosslink, remove the two bolts that hold the handbrake mechanism to the side of the diff and move the whole lot out of the way.

Just re-read the advice from earlier in the thread. So the funny looking nut will come undone. I've probably not applied enough force due to fear of breaking something. I'll have another go tomorrow night. The diff is temporarily bolted back in place so I should be able to get some more torque on things.

 

[Tom W]

You need to get the 15/16" AF bolt out from the front of the pivot, then with the nut on the back removed, (the one with the 2 "O" rings) then the pivot will come out towards the front of the car.

Thanks Harvey.

Now I know how it's supposed to come apart I should be able to make some more progress tomorrow night.

 

[Tom W]

Well, it's taken a little longer than I planned, but I've finally got the callipers off

The other good news is the previous owner's done some sorting out and has found a box of bits for the car, which includes a full Rover workshop manual

Reading the manual, I've taken a few things off that I didn't need to and in the wrong order. Removing the hand brake linkages from the callipers was a mistake as both of the little push rods have dropped out. I think the callipers need rebuilding anyway, as a lot of brake fluid spilled out from the handbrake linkage hole.

So next decision, do I rebuild the callipers myself and potentially get things wrong, of go for rebuilt exchange units and get the car back on the road faster, but at greater cost? Also, I need new brake hoses at the back, is it worth the upgrade to goodridge braided hoses?

 

[Junkman]

Brake fluid spilling from the handbrake linkage hole is normal! The shaft goes straight through a chamber with brake fluid in it, hence there is an o-ring seal and a stepped plastic washer holding it in place, where the shaft enters the housing.

Rebuilding the calipers is easy, especially when you have a shop manual. You should buy new seal kits though.

The Rover engineers did not specify braided hoses, hence neither did I or should you. This newfangled rubbish is worth bugger off. But there is a problem with some newly made rubber hoses that go between the calipers:

Since it is an old fashioned thread (I think whitworth), there are obviously not many manufacturers left who make the metal terminals, so they seem to have to use what they got. In several cases they turned out to be too long, so the hose ended up rubbing against the rear crossmember. Make sure it has the same length terminals that your original hose has, it's a tight fit as is.

 

[KiwiRover]

Brake fluid spilling from the handbrake linkage hole is normal! The shaft goes straight through a chamber with brake fluid in it, hence there is an o-ring seal and a stepped plastic washer holding it in place, where the shaft enters the housing.

No it's not!!! You shouldn't have brake fluid entering the pivot mechanism chamber. All fluid should stay firmly behind the brake piston, if it isn't your piston seal is leaking. The 'O' ring is to keep the handbrake shaft's grease in.

 

[DaveHerns]

Have a look at the bore the hydraulic piston sits in , if it's scored , get recon calipers , if not ,try a kit of new seals

 

[Tom W]

Thanks guys, I'll have a go at stripping a calliper on Saturday, see what it looks like inside. I'm favouring the rebuilt route at the moment, it's a lot cheaper and more satisfying than buying recon.

Thanks,

 

[Tom W]

Started dismantling the off side rear calliper today. The seals have definitely gone, as the mechanism and cover were full of brake fluid. I expect things have gone dry and perished in the time the car's been standing. On the plus side, nothing looks to have been messed with, and it's all complete. There are some slight differences between my calliper and the diagrams in the book, namely the posts are machined with flats to support the bar, rather than spacers.

Attached are some pics of the innards as I took it apart. I've come to a stand still now, as I can't find the correct size allen key to remove the cover plate :? There will be one in the garage somewhere.

Everything seems to be fairly straightforward so far, so I'm quite pleased with progress

I do have a few questions though, What's the best method for removing the hydraulic piston if you don't have access to an air line? Do rebuild kits come complete with the anti corrosion paper? It ripped slightly when I removed it. What grease do I need to use on the mechanism when I reassemble it? The manual doesn't say anything, but there was grease on what I've dismantled so far. How do I tell for sure whether I have metric or unified brake hose fittings? The ends fittings on the rigid pipes are conical, like the unified fittings in the manual picture, but the flexi hose between the callipers has notches on the corners of the spanner flats. I thought this signified a metric fitting.

 

[Tom W]

More progress this afternoon. I've found the right size allen key and managed to finish dismantling the calliper. A pair of pliers helped with removing the piston.

The bad news is it looks like the bore of the brake calliper is corroded slightly. Can these be re-sleeved or honed, or is it time to look for a new calliper body?