My husband and I put a new master cylinder in this vehicle recently. We bled the system but there is still excessive pedal travel. We tried bleeding the system again and had the same results. There are no apparent leaks in the brake system. What should we try to look for next to fix this problem?
Did you bleed the master cylinder before the rest of the system? That’s a first step.
Yes.
Assuming you have bled everything correctly, if you still have excessive pedal travel it’s possible you got a bad replacement MC.
What were the symptoms that led to a MC replacement? MC failure is rare on SAABs is why I ask.
What shape are the front and rear pads in? It’s possible that a self adjuster in a caliper can freeze and in turn this could cause an excessive amount of travel.
Another possibility is that the piston rod on the MC may not be the right length as the original.
If you press on the brake several times within the same short distance, say, in stop and go traffic, with no curves between braking events, is the pedal play normal? Does it become excessive again after you drive around a curve? If so, you have a loose wheel bearing allowing a rotor to move and press the pads back into the caliper, resulting in excessive brake pedal travel on the next brake event. I have seen this several times.
The pedal travel became excessive gradually over the winter. We checked all the brakes, pads etc and found them to be in good condition. We replaced the front wheel bearings thinking that might be a contributing factor and they needed done anyway. You can pump the brakes and get a good pedal feel, but it is only temporary. The next time you need to stop, you must pump the brakes again to achieve a good solid pedal feel. We replaced the master cylinder as it was the only part of the brake system that hadn’t been serviced recently. We bought this car used with 100K and it now has about 200K on it. I believe based on the service records that the former owner and the dealership printed off for us that this was the original master cylinder.
What you describe is a classic case of master cylinder failure. There are a few rubber gaskets that can allow the flow of fluid back into the reservoir, and that leads to your weak pedal.
This replacement…was it reman, or new? It’s entirely possible it’s just bad.
Update: My husband said it started doing this after he changed the brake pads this past fall. As for the master cylinder, the first replacement was from Saab recyclers, the second was brand new.
So after changing the front brake pads, replacing the master cylinder twice and changing the front wheel bearings, tie rod ends and struts, the brake pedal travel is still excessive. Any thoughts?
Bingo! You struck a nerve in the ol’ memory bank when you said it happened after pad replacement. On the front calipers are anti rattle clips facing outboard. If not installed correctly, they can cause the pads to wear on a funky angle & make for a bad pedal. One of our customers did this about a year ago.