Need to remove calipers and fix a few leaks - best options

S

StefanVXR8

Member
#1
#1
Hey everyone,

What started off as an inoperative handbrake has lead back to the rear caliper handbrake quadrants being completely seized on one side and very slow to return on the other, so I’m thinking this requires a caliper rebuild? Disks, pads etc. are all OK, and I also have a rebuild kit to do the handbrake assembled linkage.

If so, the problem I have in removing the calipers is that on one side of the retaining pin, the cap bolt has been completely mangled by someone and I’m struggling to remove, additionally on this side I have a leak from the output on the diff.

Is my easiest option to drop the entire diff assembly to allow me easy access to everything (I’m accessing from underneath on a garage floor), and if this is the best option, aside from the 3 bolts, brake hose etc. on the rear end, what do I need to undo on the main prop shaft end?

Stefan
 
M

mikecoombs

Active Member
#2
#2
There is no easy way to fix your issue(s). If possible it is good to start by first degreasing the entire diff area and pressure blasting as much crap off as you can. The hand brake mechanism can be unbolted from the diff and disconnected from the actuating lever at the caliper end. The Hydraulic pipe to the chassis can then be clamped and disconnected. You then need to remove the forward mounting bolt and tailshaft bolts (check the actual mount is ok and tightly bolted down at the same time). Then either undo the three bolts on the back plate (simplest solution but they can be difficult to locate on assembly) or disconnect the tie bar at the back and undo the two vertical mounting bolts for the back plate. You will need a commercal grade floor jack or a transmission jack to hold the diff as it is VERY heavy. I'm presuming you have already disconnected the drive shafts and removed the discs.

Once out and on the floor you can get to everything from the top. Note that the big nut for the hinge pin cover came originally with a pressed steel cap over it, so no spanner actually fits. Mostly they have been removed by now as they tend to get destroyed in the process of removing the brake unit. The underlying hex fits a UN/SAE size spanner.
 
jp928

jp928

Well-Known Member
#4
#4
On advice from people who worked on p6 a lot, I used to support the diff, remove the 3 bolts through the support plate, and carefully lower the diff as far as was safe for the brake hose. this will give you better access to everything involved. Get a tool to clamp the hose so fluid doesnt leak everywhere - same thing as pictured in manual is available.
 
S

StefanVXR8

Member
#6
#6
Thanks for the advice.

I have removed the disc on the offside. The piston is wound back fully, my main issue currently is simply that the handbrake lever won’t move on this side, and is slow to return on the other side. Is there an easy way to fix these and free them up?

I need to replace the hose connecting the two calipers and as mentioned above, fix what I think is the diff oil seal leaking, however, the connecting brake hose does have a small leak so this wetness might just be from that.

Prime concern is fixing those handbrake levers. The one that does move, will engage the pads and lock the wheel no problem, like I said, just sticky to return.

Stefan
 
M

mikecoombs

Active Member
#7
#7
Not really. The problem is the lever drives a small pin. The pin is activated by a cut out in the shaft and if you remove the shaft the pin drops out of its hole. You could try disconnecting the linkages and spraying a little wd40 on the shaft and turn it back and forth to see if you can free it up. Diff shaft seal requires removal of the axle, its bearing+housing and lock collar which is also a lot of work plus the bearing housing also mounts the caliper. They can be done in the car but its much easier and probably faster to remove the whole assembly and fix everything on the bench.
Having said all that it would be worth disconnecting the linkages from the caliper levers and checking the handbrake cable mechanism is moving freely and not stuck on one side. It works like an old school bicycle brake.
I can probably help you with parts and possibly a transmission jack but I'm in Bulahdelah north of Newcastle or Sydney. PM me to make arrangements
 
S

StefanVXR8

Member
#8
#8
mikecoombs said:
Not really. The problem is the lever drives a small pin. The pin is activated by a cut out in the shaft and if you remove the shaft the pin drops out of its hole. You could try disconnecting the linkages and spraying a little wd40 on the shaft and turn it back and forth to see if you can free it up. Diff shaft seal requires removal of the axle, its bearing+housing and lock collar which is also a lot of work plus the bearing housing also mounts the caliper. They can be done in the car but its much easier and probably faster to remove the whole assembly and fix everything on the bench.
Having said all that it would be worth disconnecting the linkages from the caliper levers and checking the handbrake cable mechanism is moving freely and not stuck on one side. It works like an old school bicycle brake.
I can probably help you with parts and possibly a transmission jack but I'm in Bulahdelah north of Newcastle or Sydney. PM me to make arrangements
Click to expand...
Thanks Mike, will reach out if required, you’re not a million miles away

I removed all the linkage and cleaned up, underneath the car is as clean as a whistle except where someone sprayed it with under seal, they didn’t remove all the linkages etc. I have a new felt washer kit to rebuild that and put back on.

The calipers, pads and discs all look really good and relatively new, the old girl had some love and care a few years ago by the looks of it and has been sat for quite a while.

Right now it is literally those quadrants that are playing me up so I’ll carry on trying to persuade them to move freely, I had a feeling there was probably a pin or something on the shaft.

Not 100% confirmed on the diff seal leak yet, I think it could be a leaking brake hose that has dripped down, mixed with some of the under seal to make it look thicker than it is. Will replace the hoses, clean up and see where we are.

Unfortunately work keeps getting in the way and slows progress!
 
V

Vern Klukas

Active Member
#9
#9
"Note that the big nut for the hinge pin cover came originally with a pressed steel cap over it, so no spanner actually fits."

This is only true for early cars. Girling changed to a solid nut that actually fits a socket, not that you can get the socket on mind you.

Yours
Vern
 
S

StefanVXR8

Member
#10
#10
So, I finally managed to remove both callipers, I found that a 15/16 spanner fitted over the cap just right and I was able to undo the swivel pins.

I rebuilt both callipers with a new seal kit, the drivers side handbrake lever was well and truly jammed but I managed to remove it finally and clean it up.

Reassembled both, got the ratchet to sound when turning the handbrake levers and I refitted both.

Passenger works perfect, both handbrake and foot brake (this was the good one before), drivers side one will not hold the disc on either handbrake or foot. I can hear it ratchet when the foot brake is applied.

I adjusted both so that the disc only just slid in between the pads. On a road test it brakes nicely, sharp and in a straight line but obviously only on 3 wheels. I also get squeal when they are hot, despite plenty of copper grease on the back of the pads and where they hang, clearly I'm missing lubricating some part!

Any ideas from the brains trust on the caliber issue, and of course the squeal...

Stefan
 
Last edited:
You must log in or register to reply here.
Top