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What is your question?
Am having a problem with the brakes on my van. Had new brakes installed about a year ago so they are in good shape. I don't use the the van that much so there is not much mileage on them. Just recently my pedal slowly started to go down to the floor and the brakes were not working properly. I took it to a friend of mine who is familiar with doing repairs on trucks. The first thing he suggested was to replace the fluid. At the time he said that the valves to drain the system were kind of rusty so we slowly started to drain the fluid from the filler cups. He did this several times while sucking out the fluid and putting new fluid in it. The old fluid was black. I left van at his house so he can work on it in his spare time. He has a garage with a lift in it. When we took the van for test drives as we periodically changed the liquid to see if the brakes would work. One thing I forgot to mention was when we step on the pedal it would go down to the floor and then all of a sudden the brakes would suddenly catch all at once and stop the van. My friend bought a master cylinder figuring that that was the cause. There was not much of a change at all. So the problem is somewhere else.Since then my friend sprayed the drain valves and was able to loosen them up. We plan to drain the whole system and put in new break fluid. This van break system has two parts.One for the front and one for the back.one filler cup is small and the other filler cup is larger.
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Here's my suggestion; IF there are no LEAKS... the original problem was indeed the mast cyl.. You now have air in the system!!.. Try bleeding the mast cyl by loosening one line at a time at the mast cyl, while helper holds pressure on pedal, tighten that line and do the other.... Then bleed brakes at the bleeder screws... IF still no luck,.. with two clamping tools,.. slim nose vice grips will work,.. pinch closed the rubber flex hoses that go to each of the front calipers... Now see if you've got a 'full' brake pedal.!!..... Post results...
Thank you We will do today
I'll check back!
. Here's what we did. We bled the brakes several times starting at each wheel. We did this several times and got a lot of air out. I got a little resistance on the pedal but still went down to the floor. One thing I noticed that we overlooked and I just caught it. You mentioned that we had to bleed the brakes at the master cylinder. This we did not do. Does that make a difference? In any case we pinched the rubber flex hoses that go to the front calipers. When we did that we got a pedal. The brakes worked on the rear wheels. But when we released one of the vice grips on the front caliper the pedal went right to the floor. We did this on both sides of the front wheels and got the same results. . My friend said that he had worked on many trucks in doing the brakes and said that this is a first for him. We should have seen fluid leaking enough to drip onto the floor. He said there is one other device ( I forget the name of it ) it could possibly be. He showed me underneath the hood where the brake lines connect to this device. I think it's some type of controller or equalizing valves. On the top of this device there is a wire that goes to the indicator light on the dashboard. He said the only thing we can try is the clean the area on and around this control device. Then try again to see if there is something leaking from this device. He put a new master cylinder in the other day.What do you think?
You still have air in the brake system!!!! That's the reason I had you clamp off the front calipers! Bleed the master cylinder like I suggested... Then bleed the FRONT brakes until you can't stand doing it anymore... Then bleed the FRONT brakes again!!!! Make damn sure the master cylinder NEVER runs out of fluid!!! .. I have a vacuum bleeder at the shop that makes this a quick & easy one man job... You just have to do it the old school way... Get ALL air out and you have fixed the brakes!!! The new master should have been properly bench bleed before installing... It may have been attempted, but was not successfuly performed... BTW.. If it were anything else, clamping flex hoses would NOT help....Let me know if I can help further and how you make out with it.. (Good luck!)
Thank you.Will let you know when we've done it.
Ok
. Hi Pushrod.Back to the drawing board. We started from scratch. My friend took out the master cylinder and made sure that he got all the air out. Re-installed the master cylinder.He borrowed a pump from work so that we did not have to bleed the brakes manually. We bled all the lines and got all the bubbles out. Tried the brakes again and the results are similar. When I push the pedal the first time it went all the way down to the floor. Then after pumping the brake pedal we got some pedal but it still felt a little spongy. So just to make sure we went back and bled both the rear and front brakes in that order. Made sure there was no air in the system. Went back to try the brakes again. Got the same results.We have to pump the pedal to get some type of resistance. When we did this my friend checked the front and rear wheels and they would not turn as the brakes were holding. Now with the engine running and if we waited a few seconds to try the brakes. The pedal we go down to the floor the first time and then we were able to pump the brakes back up where we had some type of pedal. We did this several times after waiting to push the pedal. And the same results. The pedal would go down to the floor on the first push and then will pump back up again. . So we turned the engine off and my friend said to try the pedal again. When I put my foot on the pedal there was a good solid pedal. It did not go down to the floor, it stayed near the top and it would hold and did not go down at all. It stayed solid. My friend stated that this was a good sign and that the master cylinder and the brake lines were working properly. . The only other thing that my friend could think of at this time is that there is a power booster just before the master cylinder. But he's going to try and check and do a little more research. Is it possible that the power booster could be the problem?
NO!.. it's not the booster.