HELP, bleeding brake system...

wbryanh · August 13, 2018, 08:08 AM

A little background info: 1973 Winnebago Brave D18 with front Disc's & rear Drums.

Yesterday, I installed new rotors, calipers & pads to my front brake setup. Proceeded to bleed them, including the master cylinder to the point of straight fluid, no air at all. Still nothing but pedal to the floor.

I have always done the brakes on my other vehicles with no problems. What am I missing on this thing?

Any help is much appreciated!

Bryan

Rickf1985 · August 13, 2018, 08:15 AM

Are the rear brakes adjusted properly? And did you bleed the rear brakes?

wbryanh · August 13, 2018, 10:01 AM

Rick,
At this time I did not replace the rear brakes. I did however bleed them....

BrandonMc · August 13, 2018, 10:59 AM

I purchased a reverse brake bleeder kit, and recommend that

wbryanh · August 13, 2018, 12:18 PM

BrandonMC,

Any particular brand/make, cost?

BrandonMc · August 13, 2018, 12:45 PM

I went with a pheonix systems reverse brake bleeder kit with a resevior addon, which was about 80 bucks on amazon a couple years ago. I have seen comparable kits at harbor freight as well, and those are like 30 or 40, I'd have probably gone with one of those if it holds up. There are cheaper versions, so stay away from those.

Rickf1985 · August 13, 2018, 07:31 PM

Reverse bleeders are ok I guess but I don't like them for the main reason that you are pushing an entire brake system of old, dirty fluid back through the master cylinder. It was not designed for that kind of reverse flow let alone all the crap coming back at it. I will use a vacuum bleeder before the reverse bleeder.

wbryanh · August 14, 2018, 01:04 PM

Thanks Rick!

wbryanh · August 14, 2018, 01:08 PM

Rick,
Is there a particular vacuum bleeder kit that you recommend?

Another question. Could my Master Cylinder be bad?

Froggy1936 · August 14, 2018, 01:24 PM

My hand operated vacuum pump came with a special bottle for bleeding brakes. Works very well for one person operation , Pumping a brake pedal & pushing all the way to the floor can destroy the Master cylinder, by pushing the rubber seals into and over rust and dirt in the cylinder. I think this may be what happened to your master Cly . I concur with Rick that reverse bleeders can also cause this problem on units as old as ours (may not be a problem on a fairly new veh) Gravity bleeding is also a safe way , Just needs more patience ! Frank

BamBam · August 14, 2018, 02:18 PM

Sometimes you have to just open the bleeder valve and walk away for a few hours and let it do it's thing on it's own, then close the valve. Good luck

Froggy1936 · August 14, 2018, 06:21 PM

Yep, But do not let the Reservoir go empty or you will suck air into the line and have to start over ! Best to watch the fluid coming out of the bleeder , When you see the clean fluid close the bleeder , Refill reservoir and move to next wheel The correct order is the longest line first , R/R,L/R ,R/F, L/F ! Frank

Rickf1985 · August 14, 2018, 07:01 PM

Tools are all about the same, you get what you pay for. That said, you are not going to be using it every day doing commercial work so any vacuum bleeder kit from the local auto store or Harbor Freight will get the job done.

This is what I have been using for several years and it has worked quite well.

https://www.harborfreight.com/mityvac-vacuum-pump-39522.html

wbryanh · August 15, 2018, 11:41 AM

Thanks to all that chimed in! I will get back at it this weekend and see how it goes....

Rickf1985 · August 15, 2018, 07:36 PM

If you use the vacuum bleeder there are a couple things to pay attention to. First, wrap a tiny bit of teflon tape around the threads of the bleeders to prevent pulling in air and second, do NOT pull a lot of vacuum. very low vacuum and take your time. If you pull a high vacuum you will suck air past the cups in the wheel cylinders and also in the master cylinder and fill the system with the air you are trying to get out.

wbryanh · August 16, 2018, 09:14 AM

Again, thanks Rick. Super helpful as always.
I plan to head over to Harbor Freight this afternoon.

wbryanh · August 19, 2018, 09:07 AM

Quick question, do you recommend bleeding when vehicle is fired up or at rest? Just curious.....

Froggy1936 · August 19, 2018, 12:46 PM

Any power assist is not necessary & might be more likely to cause damage to Master Cylinder from excess power applied to the pedal ! Frank

Rickf1985 · August 19, 2018, 03:42 PM

If you are using the vacuum bleeder then there should be no assist at all. But if having someone press the pedal then it is best done with engine off. Try not to push it more than halfway down.

wbryanh · August 19, 2018, 06:02 PM

Okay, all brakes bled by vacuum bleeder. Still no brakes, all sponge. Oddly I was able to get it down my steep driveway, braking midway, no problems. Once I got on flat ground and gave it gas, had to use parking brake to stop, in other words no brakes at all to the floor!!!
Any ideas?
Master Cylinder? Part # if so......

Thanks!

Rickf1985 · August 19, 2018, 07:52 PM

Have you adjusted the rear brakes? Are you sure you got all the air out? Was the master cylinder empty at any point? If so you will probably have to bleed it separately, if that is the case replacing it is probably a good idea since it will be off anyway. Be sure to bench bleed it according to the instructions that come with it. Short strokes until you stop seeing air from the return valve in the reservoirs.

On edit, I just realized we are talking about a Dodge here, does this have the dual master cylinders under the chassis? If so you need to get hold of Dave on here, that system is his baby.

wbryanh · August 19, 2018, 07:56 PM

Pretty sure I have the dual chamber, one master cylinder with brake booster attached.

Rickf1985 · August 19, 2018, 10:15 PM

Ok, I am not really the expert on the Dodge brake systems but a lot of them had a dual booster system on the frame rail. I don't know if Dave got his page back up yet but he has a ton of info on Dodge brakes. If you have rear drum brakes you really need to check to see if the shoes are adjusted and all the springs are in place. That means you may have to pull the drums. If you are positive there is no air in the system and there are no leaks but the brakes were working before then it is either the rear brakes or the master cylinder. Open a rear bleeder and have someone push the brake pedal and see if you get a good squirt of fluid, again, try to refrain from going to the floor. If you get good fluid then the master cylinder is probably good and you either still have air or a rear brake problem. This has disc front brakes? I am assuming it does, if not then the front brakes could need adjusting.

wbryanh · August 20, 2018, 08:14 AM

Im leaning toward just replacing the MC, seems as though all signs are pointing in that direction.

I never touched the rear brakes as far as repairs go. I did however bleed them during this process. They appeared to have good vacuum seal and recieving plenty of new clean fluid. The breaks were absolutley working prior to me rebuilding the entire front braking system, as I have had it on the road for nearly 9months.

How can I get in touch with Dave, to ensure I am ordering the correct parts for my 1973 Winnebago Brave?

Rickf1985 · August 20, 2018, 10:06 AM

I checked and his site is still not back up but here is his contact info. Send him a PM and he should get back to you. I know he is always busy so it may not happen instantly.

http://www.classicwinnebagos.com/forum/index.php?action=profile;u=321