brake bleeding tips

[DetroitDan]

While adding tailpipes to my glasspacks, I 'touched' a brakeline and it started seeping, so after a huge battle I got it off and replaced it. It was a short piece that went between the rear brake hose and the overload brake lever thingy. So now, obviously, I need to bleed them, and my past experience has been that 30 year old brake bleeder screws don't like to come out. Which means replacing the wheel cylinders. Never used to bother me, BUT, now we are talking about a full floating rear axle. I have to hoist this thing up in the air (outside in the dirt), pull 4 tires off, unbolt both axles, then hope and pray the drums will come off, which they probably won't without convincing from an 8 lb sledge. So that's what I'm hoping to avoid.

To make it more interesting, this is the narrow cab & chassis rear axle, so it's got about an inch and a half between the backing plate and the spring pack. Sprayed it down good today with PB blaster, but after trouble I had seperating the brake hose from the brake line, I'm not anticipating any luck. Also, I have no heat wrench.

Any pointers? I don't mind buying a tool when I need it, and I don't mind replacing parts that are old, but I don't want to blow $600 getting ripped off by a shop.

[BMERDOC]

Try gravity bleeding followed by a two man brake pump. Remind your pedal pumper that they aren't trying to shake up a beer, nice deliberate, top-to-bottom, slow pumps. Add a short piece of vacuum line to the bleeder end to eliminate bubbles. Hopefully the proportioning valve hasn't popped or you'll have to reset it by pulling the pin. Try turning the bleeder and if it snaps off get a new cylinder, you'd need one anyway by that time.

[donut]

Better it happened while doing the tailpipes than going down the road.
New England and brake lines= bad (Every couple of years, there was at least 1 to replace)
Maine would fail you on a state inspection if the lines were rusted.

Wire brush the bleeders, soak them down with weasel p, repeat in a day or so.
I used a 6 pt. socket to break them loose, (lightly tap the handle with a hammer to shock them) then go to a wrench to bleed. I also used a one-man bleeder set-up. vacuum line to the bleeder, submerged in a bottle with a little brake fluid in the bottom, that way you don't draw air back into the system. When brake fluid in the bottle doesn't show little bubbles, you should have it.

My full-floater I was able to do 1 wheel at a time, if needed.

[hatzie]

Gravity Bleeding usually works unless you have air in the master cylinder. Center the combination valve then bleed from the longest circuit to the shortest (LR, RR, RF, LF).
I built a pressure bleeder with an ACE Hardware insecticide sprayer and pressure gauge. Even if you buy the cap from Motive Power you can build it for less than $50. Once you've used a pressure bleeder you'll never want to do it any other way.
Here's the Motive Power 1105 cap. It's not rocket science to make your own but it may be worth $36 to just buy the cap.

Here are several DIY howto articles on the bleeder.
http://www.bmw-m.net/TechProc/bleeder.htm
http://www.yotatech.com/f106/30-00-d...leeder-211977/
http://faculty.ccp.edu/faculty/dreed...eder/index.htm

[maromero1973]

Wax and good flare wrenches.....
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[DetroitDan]

I have a little bottle and line kit I bought so I can do it myself, but the actual bleeding isn't at all what I'm worried about. It's just cracking the bleeders loose that I'm really really worried about. Especially after finding the brake line and brake hose that was cranked together so tight it took every bit of strength I had to separate them with two brand new pairs of vise grips.
Going out to get started as soon as I finish my coffee. Thanks for the advice, wish me luck!

[86Burban]

Agree with all of the above, expecially wire brushing and spraying the bleeders for a couple days. Personally the combination of that and the correct fitting wrench has been very successful for me over the years and many differents vehicles.

As far as bleeders/pumps...I have both the Motive Power Bleeder and Powerfill. No, not the cheapest to buy but I have used both with zero issues many times. I highly recommend both of them for brake bleeding, diff/t-case fills, etc..

[DetroitDan]

probably cheaper to buy than a visit to the local automotive repair facility. $70 hr labor adds up pretty fast.

[DetroitDan]

Well. I couldn't get on the bleeder with a socket, well I could get the socket on but no room for a ratchet. Couldnt get fitting wrench over it either. There's just no room in there because it's a C&C. SO...I had to do something, so what I decided to try was to bleed it from the new connection I just made at the top of the rubber brake hose where the new lone off the valve connects. Only thing I could get apart without ruining it. Figured I should be able to at least fill the new line with fluid, and to heck with the two going out to the wheels.
Worked better than I expected. Didn't take that long either. Flushed out a lot of old black fluid too. I could hear the rear brake shoes working while I had someone pumping the brakes. So the pedal feels good and I took it for a ride, stops as good as it did. Brake light comes on randomly, but it has always done that and I don't know why. If I stand on the pedal I can lock up the fronts, but I'm not too surprised, the roads are wet and the front tires are skinny. Otherwise it seems to be functioning well. Which is weird, because I didn't expect that to work that well...
Anyone know what the light is sensing? It was on the whole time my e-brake cable was disconnected, although I don't see how it's tied into that. I don't have a low fluid problem at all. It's hydroboost, so I checked power steering fluid and that's good too. All I can see is a harness plug going into the brake master, maybe it's reading an air pocket or something.
Eventually I'm going to have to go all through it, change all the lines and wheel cylinders, etc. I think the rear brake lines are original-they still have that coil wrap stuff on them. Is that even possible? 30 years old? But for now I think I'm on the road again. Thanks for the input.

[donut]

DetroitDan, try tying up the e-brake pedal. There is a switch on the e-brake that works the light also, (at least it did on my '73.)

Glad it worked out for you.

You could still have the original lines, it seems the new ones rust quicker than the originals.

[wyattglock]

If you use the Motive #1105 adapter to try and bleed the brakes, I had a lot of problems getting the adapter to hold a seal. So I got a 6 inch c-clamp and cut a piece of c-channel steel to the length of the adapter. Clamped it to the master cylinder with the c-channel on top and didn't have any more sealing issues. I didn't have to crank on the clamp either, just enough pressure so it won't slip around. Just an fyi, good luck getting them straightened out.