I just want to say that I have worked on the brakes on many vehicles in my time: 61 Cutlass, 66 Chevelle, 77 200SX, 81 Corolla, 82 Virago, 87 Supra, 88 Hi-Lux, Tacoma, 98 Passat, 89 Grand Voyager, 95 Civic, F350 Super Duty, Schwinn, Huffy and others I cannot remember. I have never had nearly the trouble with the brakes that I have with our 99 Grand Caravan....
96 Grand Caravan Brake Issue - Feels like air but doesn't seem to
I have a 1996 Grand Caravan ES with anti-lock brakes. I hadn't opened the system for quite a while and the last time I did I fully bled it and the brakes felt great. The other day, the brakes just started to feel a bit spongy on the way to work. On the way home they felt a LOT spongier. I had to pump the brakes to get them to stop the van, but they did work once pumped. It feels like there is air in my system, but I didn't open it and it came out of nowhere. I have inspected the whole system and can't find any fluid coming out anywhere so I'm not sure where any air could get in if there is any.
I did have my brake light come on going around a corner a couple of time a few weeks back. I assumed the fluid was low as the light turned off after I completed turning the corner each time. Anyway, when I got home I went to top off the resevoir and it was already full. The little bit of fluid I added just filled up the filler neck. I didn't see the light come on again after that, though.
Anyway, fast forward back to the issue. I bled out the wheel cylinders and got some nasty fluid out, but not any air. The fluid coming out of them now is nice and clean, though. I went to bleed the front calipers and broke off both bleeder screws (they were frozen in). The broke off in the sealed position, though, so I bled them at the brake lines going into the calipers. The pedal was still spongy, but it still stopped the van so I kept using it.
I ordered new calipers and did some research. A bad brake booster would make for hard applies. That isn't my issue, mine are really soft. A bad master cylinder with an internal leak should have pedal fade. I don't have any. You have to pump the brakes to get the brakes to apply decent, but once they're on, they're on. They don't fade towards the floor as I sit at a traffic light. I kept an eye on my fluid level and it wasn't going down at all (no external leaks I can find to let fluid out or air in). I was hoping there was somehow air in the top of the calipers although I have no clue how it would've got in.
Anyway, the new calipers arrived today and I put them in and bled the front brakes. The van feels the same as before. I'm kind of scratching my head on what to do next. I needed new calipers anyway since the bleeder screws broke off, but I also have something that allowed the system to suddenly feel like it full of air when I can't find any while bleeding (and I was thorough). Any experience anyone has had that could explain this mystery to me?
I did have my brake light come on going around a corner a couple of time a few weeks back. I assumed the fluid was low as the light turned off after I completed turning the corner each time. Anyway, when I got home I went to top off the resevoir and it was already full. The little bit of fluid I added just filled up the filler neck. I didn't see the light come on again after that, though.
Anyway, fast forward back to the issue. I bled out the wheel cylinders and got some nasty fluid out, but not any air. The fluid coming out of them now is nice and clean, though. I went to bleed the front calipers and broke off both bleeder screws (they were frozen in). The broke off in the sealed position, though, so I bled them at the brake lines going into the calipers. The pedal was still spongy, but it still stopped the van so I kept using it.
I ordered new calipers and did some research. A bad brake booster would make for hard applies. That isn't my issue, mine are really soft. A bad master cylinder with an internal leak should have pedal fade. I don't have any. You have to pump the brakes to get the brakes to apply decent, but once they're on, they're on. They don't fade towards the floor as I sit at a traffic light. I kept an eye on my fluid level and it wasn't going down at all (no external leaks I can find to let fluid out or air in). I was hoping there was somehow air in the top of the calipers although I have no clue how it would've got in.
Anyway, the new calipers arrived today and I put them in and bled the front brakes. The van feels the same as before. I'm kind of scratching my head on what to do next. I needed new calipers anyway since the bleeder screws broke off, but I also have something that allowed the system to suddenly feel like it full of air when I can't find any while bleeding (and I was thorough). Any experience anyone has had that could explain this mystery to me?
