| Author |
Message |
Richelson (Richelson)
Member
Username: Richelson
Post Number: 621
Registered: 12-2001
| | Posted on Monday, March 18, 2002 - 6:46 am: | |
When I said spongy I should have used a better description. What I was the effort to push the pedal but is has the feeling of cheap brake pads. It is hard to describe. Thanks for the info. It sounds like(from reading Brets post) changing the vacuum hose isn't very easy at all. |
Henry D. Chin (Hanknum)
New member
Username: Hanknum
Post Number: 7
Registered: 2-2002
| | Posted on Monday, March 18, 2002 - 12:56 am: | |
If you are experiencing a "spongy" pedal, you may have air in your system. Try bleeding the system first. |
Richelson (Richelson)
Member
Username: Richelson
Post Number: 618
Registered: 12-2001
| | Posted on Sunday, March 17, 2002 - 7:59 am: | |
Great info. Thanks Ed. The effort required to brake never changes, when in neutral, slowing down, coasting, all take the same stopping power. I am not sure if this helps on troubleshooting but I just thought I would add this info. I will go out and check it today. |
Edward Gault (Irfgt)
Member
Username: Irfgt
Post Number: 893
Registered: 2-2001
| | Posted on Sunday, March 17, 2002 - 6:22 am: | |
With the engine running, remove the vacuum line from the booster and see if you have good vacuum on the hose. Ideally the engine should stall. If there is not good vacuum there then remove the hose from the engine and look for similar results. If the hose is not leaking and you still have low manifold vacuum , an exhaust restriction is possible. If your brakes are more powerful during deceleration a vacuum problem is probably the cause. If you have good vacuum on the booster then the booster is probably at fault. A bad booster will cause a very hard pedal and require hard pedal pressure to stop. You can also remove the hose from the booster and plug the hose and test drive and compare the before and after feel for comparison. |
Joel Ames (James)
New member
Username: James
Post Number: 32
Registered: 4-2001
| | Posted on Saturday, March 16, 2002 - 3:52 pm: | |
Check to make sure you put the check valve in the vacuum line in the proper direction. Just a thought. |
Richelson (Richelson)
Member
Username: Richelson
Post Number: 614
Registered: 12-2001
| | Posted on Saturday, March 16, 2002 - 3:13 pm: | |
On my 78 308 the braking isn't as sensitive as I think it should be. The QVs I have driven all have very sensitive braking IMO and when you start to rest your foot on the brake it starts stopping and stops easy. My 78 will brake but seems to be spongier and takes more effort but not to where the vacuum assist isn't working. When I put the QV in neutral and use the brakes it can be very hard to brake as the assist isn't working and my 78 isn't this hard but more spongy I guess. What can I check? I can change the pads, turn the rotors, and put on a new vacuum line. I don't think it is vacuum though it feels different. Any thoughts would be helpful. What happens if the booster isn't functioning properly. Do 78s naturally brake harder than Qvs or should they be the same? |