OldnDecrepit My 1990 740 GLE is in need of new brakes for the rear as the pistons in the current ones are dragging. The options seems to be to buy whole caliper units (new or refurbished) or buy a kit and get them refurished by my local mechanic. My inclination is get new ones as the car is now 26 years old. The VIN is YV1744896L2481452. What does everyone advise and where might I get new ones in OZ?
Vee_Que They ran the same calipers on 850s and c70s, so a brake shop should have no real issue in getting a kit and rebuilding them. Its quite simple to do really.
OldnDecrepit One problem is that there are three different piston sizes for my model. But I suppose that once the caliper is removed we'd find out the size.
Angus242164 Are the brake hoses original? It's not uncommon for the inner lining of the hoses to perish and swell, blocking the hose. Pressure from the master cylinder will push past the blockage, but the fluid downstream of the blockage doesn't have enough pressure to return, and the pistons hold on and the pads drag. To test for this, undo the bleeders and see if the calipers release. If they do, it's in the hose (or something upstream of the hose), if they don't, the caliper pistons are seized. I'm looking at offering professionally rebuilt calipers for the rear wheel drive models on a change-over basis in future, but I'm not fully set up to do it yet.
Rob All of this. Check the lines first. There is almost no difference in rear calipers from the 144 right through to the P80 (except AWD) Really early ones require very slight mods to fit, later ones are all identical. Apparently there are a few different piston sizes but everything I have seen is the same, suggests to me that the other sizes are rarely used.
Vee_Que Which is what I've said twice. The irs cars use a single piston car, that is all 760s from 1988, and the 960s.
OldnDecrepit Here's some pictures of the left rear caliper of my 740. It looks like it has 38mm pistons. The 960 ones I have are single pistons but much bigger.
