Replacing rear brake lines

[OS]

I need to replace the rear brake lines because of rust (they failed MOT).

The object is a -92 LPT with ABS. The question is, does the configuration of the lines vary between models?

I've found a kit of pre-cut coppelines that alledgedly should fit all 900s from 81-93 (Biltema), but I am sceptic.


cheers
/Oskar

[philb]

ABS cars are different, there is only 1 line running to the rear, this runs to a t-junction on the axle. I'd imagine a kit for 81-93 would be non-abs, you need to check out what pipes are in the kit. If you can find a picture of it, post it up.

[OS]

Thanks, you're right.

I called a supplier, it seems to be two pipes on the ABS. One 44cm and one 98cm. He's cutting them for me, and hopfully I can bend them in shape.

[OS]

The haynes manual i crap on this issue. Does anyone have a diagram on the how the hydraulic pipes are routed?

cheers
OS

[900t]

One goes on the axle from one soft line to the T junction, the other goes from the T junction to the other side wheel. It is offset towards the right. It seems odd because the brake line runs on the left side of the car under the kickplate under the door but trust me.

[OS]

Excellent! Thanks alot.

I need to order the S-bit too. That is the missing third bit that they did not find at the parts-store. Anyone have an idea how long it is?

[OS]

I am planning how to bleed the rear circuit of the ABS-system after replacing all pipes(3) on the rear axis, and need some comments on the procedure.

Hopefully I can get away with only bleeding the rear brakes. The idea is first to try to not get too much air into the system by sealing the cap to the fluid reservor and to clamp the rear break hose before starting.

I have a home built pressure bleeder (a cap with a bicycle valve), can this be used, or should I use the ABS-pump like described in Haynes?

Cheers
O

[philb]

Ok, you need to use the abs pump for the rear brakes. You need to give the pump a break in between each bleed, or it will overheat. There are other threads on this subject, I'm pretty sure I had one myself when I was sorting out the rear brakes on my car.

[Rodentmaster]

For what it is worth..........

I believe that the reason the brake line/s and fuel lines enter/exit the floor on the right side is that it is the opposite side to the exhaust pipe and thus are subjected to the least amount of heat stress or heat soak, possible.

I could be wrong but that's not unusual!

[philb]

That reminds me. OS, you should really change the flexible lines from the body of the car to the axle, for proper braided hoses at this time.

[Jim Mesthene]

Originally Posted by OS

I have a home built pressure bleeder (a cap with a bicycle valve), can this be used, or should I use the ABS-pump like described in Haynes?

Use your pressure bleeder after following your procedure of capping lines etc.; it's safer for you and your car. Make sure the reservoir never gets empty or you'll have to cycle the ABS valves to remove air you've pumped in.

[OS]

So to clarify, it is possible to bleed the rear circuit with the pressure bleeder despite the ABS blocking the way?

cheers
OS

[Jim Mesthene]

When I went to the SAAB ABS school in 1987, pressure bleeding was the recommended method for routine flushing or bleeding after repair.
DO NOT allow air to be forced into the system or you may need to cycle all ABS valves with an ISAT or equivalent to get air out of the valve body.

[Matthew]

That's interesting because the Saab service manual says to use the ABS pump to bleed the front brakes, and a pressure bleeder for the rears.

I would have loved to go to Saab school How cool would that have been?

[OS]

Any clever Ideas on how plug the line while changing pipes?

I was thinking about cutting a pice of rubber in shape of a cone to push in, but maybe there are pre made pluggs for this purpose?

[cdaly]

If you seal the brake fluid reservoir lid {it has a vent in it}, very little fluid will leak out. Put enough rags to catch what fluid does drain out and fit the new hose promptly. I'd suggest you leave this hose until last thing. Clamp the old hose to reduce leakage while you have the brake lines off the axle and, once the new lines are in place, replace the hose.

[cdaly]

Be careful when bending the brake lines. Make sure you use some kind of former {like your thigh} so the lines don't kink...

[OS]

Yes it is a little bit scary bending the pipes, as shown in the picture above, there are a few 90degree turns, an the small pipe is shaped as a fairly tight S.

[Matthew]

Pipe benders for copper tubing are cheap to buy. Best to make your bends on one of those than risk kinking the piping IMHO. You can buy benders for even the really small pipe found on car brakes.

[Mr.Wallace]

Hello

Would anybody be able to recommend a suppler in the UK of the item labelled 13 in the diagram posted by 900t?

I believe it is a 3 way oil splitter, I also need to replace all the rear hoses and metal lines on the rear ASAP.

Thank you.