My brakes won't bleed. =~(

On my last outing, and Trish's very first off-road event, I blew a proportioning valve on the Samurai. It blew coming DOWN the mountain. We drove through the village of Lake George with 15 jacked up and tired up Jeeps to attend a Bar-B-Q and when the Sammy pulled hard left on braking I explained there was something in the road I had to avoid. I wasn't about to tell her we were driving 50 miles home with no brakes. I just down shifted a lot.

I put the new proportioning valve in and started bleeding out the air. I started at the right rear, farthest from the master cylinder. Because I can't pump the pedal and crank the vent alone and I don't always have an extra leg in the garage, I bought a vacuum bleeder. Nice. Squeeze it a few times and crack the vent, nothing to it. I went around the car twice and still have to pump up the pedal to get some resistance. I don't think I emptied the master cylinder in the process, but if I did and didn't notice, do I have to start there? How do you bleed the master?

Dan

BTW: Trish had a good time, got out and walked around a few obstacles, got slammed around inside the cab a bit, but said she would do it again.

Dan,

Place a couple aluminum disposable pans under where the bake fluid will fall loosen the bleeders and slowly depress the pedal about (and no more than) 1/4 way, this should get the mess flowing, then keep pouring fluid in until it flushes all the old crap out.

Once you are getting clean fluid flow you should be able to remove the rest of the bubbles quickly.

Generally to bleed a master cylinder still on the car/truck I jack the back up to get the reservoir level. This generally removes any trapped air in the MC.

Do you have ABS? Getting those bled sometimes requires special tools and lots of patience.

Do you have rear drums? I have melted the seals inside the rear wheel cylinders off roading before and took me while to find the air leak since the fluid loss was negligible.

I got one of those mighty vac vacuum testers/brake bleeders... One time I was trying to use it... I could see it sucking tons of air bubbles out, progress looked good... But the bubbles kept coming and no way was there THAT much air in the system.

Realized that all it was doing was sucking air in around the bleeder screw, into the caliper, then back out of the caliper through the bleeder screw. Maybe something like this?

One thing an autoshop teacher taught me, and has actually worked (all be it slowly) is to just open the bleeder valve and let it sit there... Since the master cylinder is higher then the bleeder valve fluid will slowly come out, with out needing to pump the brakes. He said when he worked as a mechanic rather then splitting hours with someone else to bleed brakes he would just top off the master cylinder, open all 4 bleeders at once, hook up some hoses into a cup and go do something else occasionally making sure the master didn't run dry.

I've never done 4 at once, and don't know that I would leave it unattended and risk draining the master cylinder but I have had success doing this one wheel at a time when I am without an extra foot.

alternatly, since you have a vacum bleeder, you can probably reverse fill the system if you can switch your bleeder from vacum to pressure. I do this frequently with my mighty vac kit when doing the brakes on alot of forklifts that have brake components above the master cyl. Fill the bleeder cup with clean fluid, make sure you have a siphion tube on the cap of the bleeder cup that goes down almost to the bottom of the cup. next connect the plactic tube to the bleeder nipple on the caliper or wheel cyl and to the outlet of the bleeder cup that the siphion tube is also connected to, switch the mighty vac pump to pressure and connect a tube from the pump to the other connetion on the bleeder cup cap. crack open the nipple on the caliper and start slowly pumping pressure into the bleeder cup. the air will displace the fluid in the cup and push it through the lines and into the brake system. as the new fluid is pushed into the system it will push out the old fluid and air bubbles into the master cyl resivior. It might take along time to do a car this way, but this method usualy work when all else fails. one thing to be cautios of when using a vaccum bleeder to suck air out of a brake system, especialy drum brakes, the vaccum can suck on the wheel cyl so hard that it will pull air from around the nipple into the tube, or if your wheel cyl seals are not in great condition it will even pull air through the pistion seals of the wheel cyl.

I have gravity-bled brakes plenty of times, and it does work, but these were all systems with everything in good working order. Some sort of pressure will likely be necessary. I got myself a pressure bleeder a few years ago, and it is clearly the way to go. Way better than vacuum bleeding for the reasons mentioned, and you can fill the reservoir with as much fluid as you want and just let it flush through slowly if the system needs a good cleaning.

http://faculty.ccp.edu/faculty/dreed/campingart/jettatech/bleeder/index.htm

I want to build one of those.

sounds like you may have an air bubble in the new prop valve.

ignorant wrote: http://faculty.ccp.edu/faculty/dreed/campingart/jettatech/bleeder/index.htm I want to build one of those.

My buddy has one of those, a kit with a hand pump and an assortment of different caps for different cars. I like the home made idea. This weekend I'll try pushing fluid up the system backward.

Thanks for the help guys.

Dan

Another option:

Get another master cylinder cap from a junkyard and drill/tap it to fit an air chuck fitting. Run your air compressor into it. Turn pressure down to ~10 psi. Open bleeders, pressure bleed system.

Another option:

Get some brake lines bent up to run from the outlets of the master to the reservoir of the master and pump it a few times to get the air out of the master first.

Another option:

Remove bleeder screws entirely and make sure they are clean and free from debris. A blockage in the bleeder screw can cause trouble bleeding brakes.

I've got brake issues on my samurai also, so I'll be happy to hear how it comes out for you. I've done the gravity bleed thing before (not on a Samurai, yet) and had it work (I've also had it not work...).

My samurai has a brake system leak I haven't been able to find yet . The master cylinder was all grimy, so I suspect it was possibly the reservoir seals. I've cleaned and reinstalled everything and need to check back to see if it's leaking there, or if I need to start taking drums off....

Clem

914Driver wrote:

ignorant wrote: http://faculty.ccp.edu/faculty/dreed/campingart/jettatech/bleeder/index.htm I want to build one of those.

My buddy has one of those, a kit with a hand pump and an assortment of different caps for different cars. I like the home made idea. This weekend I'll try pushing fluid up the system backward. Thanks for the help guys. Dan

We built one. It changed the way brakes are bled around here!

That was an interesting DIY. I've thought about adding a tire stem fitting to a bug sprayer anyway to avoid all that pumping. However, their approach will never work around here. You can't get any of that clear plastic tubing. The meth labs have bought it all up.

Personally, I prefer the two person method, but when I'm by myself, I do this:

I use a nasal canula oxygen hose. The oxygen cylinder end is perfect for fitting over a bleeder nipple. Then you crack the bleeder a little and put the other end of the hose in a picante sauce jar. Texas made picante sauce, of course. New York made picante sauce jars won't work. Pump the brakes. You should be able to see brake fluid and bubbles flow through the line. If it is going too slow, open the bleeder more. Make sure the distal end of the hose stays under the fluid that is accumulating in the jar. If you're flushing the fluid, you can see the color in the tubing. Make sure you don't run the MC dry. When your getting close to done, that is, the fluid in the line is clear and there are no bubbles in the line, crank the bleeder down to where there is just a little coming through when you step on the brake pedal. Then push down, ease up slowly, tighten the bleeder. Go to the next wheel.

Well, I sucked and vented the system again using the vacuum pump, this time I kept the pressure lower and saw much smaller bubbles. I now have a solid pedal with one or two pumps. There's still air in there, but I'm sneaking up on it.

Dan

is there a bleeder on the prop valve?

My toytota had one on the rear prop valve and if you didn't bleed it the rear brakes were slightly inconsistent in operation to say the least.

No beeder on the prop valve.

Pressure bleeding is a good idea. My milano is terribly for bleeding the brakes, the best way i have found is pressure bleed until its driveable, drive it for a week or two, bleed again and get more air out, repeat as nesessary. lol

have you tried a shotgun yet?

Dan is more of a rifle man if I remember.

Hey Dan...

Where are the bleeders on the rear drums of your samurai? Upon quick inspection...I only see one on the starboard side of mine. Is there another back there?

I know I just need to crawl under there and find them...but I'm at work and the samurai's not ;).

Thanks, Clem

Yep, port side. It's part of the wheel cylinder on the inboard side of the drum at about 12 oclock.

Hey, maybe you got lucky and it just broke off so now you don't have to do it!

Dan

I generally will bleed just after a component replacement, like the proportioning valve, by leaving the tube nuts on the output side loose then work the pedal slowly. Once no more air comes out, tighten the tube nuts. That way I don't have to push air all the way to the end of the system. Also, a long shot: does the Sammy have one of those height actuated rear proportioning valves like your 914? If so, they can be a beeyotch to bleed unless you take the link loose and raise the actuating arm.

Thanks!

I think I got my sides mixed up (laying under a decaying vehicle can disorient a guy, afterall)...but nice to know I'm not dotty for only finding one of them on the hind end.

It looks like they forgot to design in the crosover brake line between the two and just decided to use the bleeder port to route the line to ;).

Clem

I installed speed bleeders, works great, no need for a helper or fancy equipment

2' of tubing, no help from others required.

As much as I want to love pressure bleeders, they tend to make a mess.

Air rises, many people forget this, and leave air in the lines as a result. Bleed high points, like where the line joins the master cylinder. Often times, air is hiding in places like this and doesn't come out with normal bleeding.

ClemSparks wrote: It looks like they forgot to design in the crosover brake line between the two and just decided to use the bleeder port to route the line to ;). Clem

You know..... I read that three times. Say it again. They screwed the brake line into the bleeder hole? What's in the brake line hole?