SaabCentral Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
66 Posts
Discussion Starter #1
Background: bought car from curbstoner who'd bought it at auction and it came with original owner's pink from 1995 and had year's back DMV, so I figure it sat for at least a year (in mild San Jose, CA)


put about 3500 miles since then and now brakes are going soft but come back up with one pump. Brake fluid in Master looks rather dark amber!:eek: Is that a Saab thing?


I didn't notice any wetspots when I got new tires but brakes were acting up at the time either.


Weighing sequence (and parts purchases) to solve problem. Need pads all around. I guess I should buy pads AND Slave cylinders so if when I'm doing pads I notice any leaks I'll have the cylinders, and if I don't notice any leaks at the wheels that means it MUST be the Master going bad???


Any diffs in symptoms between if its Master VS Slave cylinder going bad?


Will Master go bad without showing any leaks? Do Slaves always leak when going bad?


Any weird Saab stuff I should know regarding the brake system? (I've done cylinders and system bleeding before but its been a while)
 

·
Registered
Joined
·
7,077 Posts
There is no "slave cylinder" in a brake system... the "slaves" are the brake calipers.

Dark brake fluid is either old fluid, or fluid which is contaminated by failing rubber in the system.
 

·
Registered
Joined
·
9,355 Posts
Try pressing the brakes gently. Does the pedal sink slowly?

If so, hit the brake pedal quickly. Does it hold?

If yes to both, then seals in the master cylinder are failing. Master cylinder needs replacing.

If the pedal only sinks slowly with hard pressure, there's likely a leak somewhere in the lines or calipers.

Sometimes it's easiest to feel what's going on by keeping the car turned off, and pumping the pedal a few times to exhaust the vacuum assist. Then do tests, you can better feel what the pedal is doing.
 

·
Registered
Joined
·
66 Posts
Discussion Starter #4
Try pressing the brakes gently. Does the pedal sink slowly?

If so, hit the brake pedal quickly. Does it hold?

If yes to both, then seals in the master cylinder are failing. Master cylinder needs replacing.

If the pedal only sinks slowly with hard pressure, there's likely a leak somewhere in the lines or calipers.

Sometimes it's easiest to feel what's going on by keeping the car turned off, and pumping the pedal a few times to exhaust the vacuum assist. Then do tests, you can better feel what the pedal is doing.

good info;ol;


however, results are "kinda and sorta", I wouldn't be surprised if both things are happening.


When driving and then hitting brakes gently, it seems to fall away alarmingly easily, but one pump brings it back, but it will then fall away gradually.


I'm guessing dark fluid at the Master can only mean Master's rubber seals are failing.


https://www.autozone.com/brakes-and-traction-control/brake-caliper-front


Any reason why "without bracket" is $19 more than "with" for same brand?
 

·
Registered
Joined
·
9,355 Posts
good info;ol;


however, results are "kinda and sorta", I wouldn't be surprised if both things are happening.


When driving and then hitting brakes gently, it seems to fall away alarmingly easily, but one pump brings it back, but it will then fall away gradually.

Almost certainly the master cylinder seals, then.


Has there been any drop in the brake fluid level?


If the brake fluid level is staying constant, then the master cylinder is shot and needs to be replaced.


Any reason why "without bracket" is $19 more than "with" for same brand?
I don't know which one you are looking at. Most of those don't look anything like an NG900 caliper. Anyway, those aren't the parts that you are looking for.


https://www.rockauto.com/en/catalog...265813,brake+&+wheel+hub,master+cylinder,1836
 

·
Registered
Joined
·
66 Posts
Discussion Starter #6
Almost certainly the master cylinder seals, then.


Has there been any drop in the brake fluid level?


If the brake fluid level is staying constant, then the master cylinder is shot and needs to be replaced.



I don't know which one you are looking at. Most of those don't look anything like an NG900 caliper. Anyway, those aren't the parts that you are looking for.


[URL]https://www.rockauto.com/en/catalog/saab,1995,900,2.3l+l4,1265813,brake+&+wheel+hub,master+cylinder,1836



Fluid about 1/2 between max/min, I guess I'll mark current level with Sharpie. Here is caliper, but maybe AZ uses generic pics or something. https://www.autozone.com/brakes-and...ted-brake-caliper-19-b1803/565886_341383_5913


I guess I'll do the Master first because:


Fluid looks nasty, and when I do the pads and bleed system I'll take better look at calipers.


One of my old 93 900 had Master go bad but never had caliper go bad.


Any tricks to swapping the reservoir on Master?
 

·
Registered
Joined
·
7,077 Posts
Pull really hard!

Make sure you lubricate replacement grommets with brake fluid before installing a new master to avoid damaging them.
 

·
Registered
Joined
·
884 Posts
What about the brake booster? There are some posts around that have a specific test procedure which helps determine if sloppy brakes are from master cylinder or booster. The master could also be leaking into the booster and pooling in there if you are indeed losing fluid.

Make sure you flush all the fluid before adding any new parts. Well worth a $50 investment in a pressure bleeder that has a European/Saab brake reservoir cap adapter and a lot of synthetic brake fluid. I was amazed at what came out of my '01 Viggen lines. It took a long time and a lot of fluid to get clean fluid out of every caliper. there were some nasty particles which I believe played a part in clogging the ABS unit which I ended up swapping out.

When I replaced the master on my Viggen I bench bled, jacked the car so the master cylinder was level, installed and bled the system. I read somewhere that an air bubble can get in the master if its on an angle and you can't bleed it out if it's not level.
 

·
Registered
Joined
·
18,370 Posts
Front calipers typically last forever unless the bleeders rust beyond repair... then you can usually still get them out and just replace the bleeder screws. In CA you won't typically have the bleeder screw rust issue.

The rear calipers are almost always rusted/gummed in place if these cars sit for a long time. In the Rust Belt, they are rusted even when used continuously. You might get a break in CA on that point... but check the rears to see if the pistons are moving. A good indication of that would be a rusty rotor that stays that way on either side.
 
1 - 9 of 9 Posts
Top