pump,pump,pump

[Blue Cloud]

Wish me luck, headed out the door to go through the rear brakes on my 71 F250. I got a problem somewhere, I have to pump the brakes everytime I step on them. I did a brake job on it last fall ( new shoes, drums turned, rebuilt the wheel cylinders) then bled the lines ( several times) still had to pump it two or three times, then they would be great until I took my foot off the pedal, then I'd have to pump again. Then changed the master cylinder and same thing, pump, pump, pump all the brake in the world until I took my foot off the pedal then pump again. I thought I got a bad master cylinder, changed it out this spring, same thing. So I'll go back into them and look everything over and fix anything wrong I find. If that don't work I'll be really confused. Cross your fingers (mine will too busy) Let you know how it goes!

[BigRedTruck]

would air in a system do that?

[jzjames]

Yeah I also have to pump twice every time I brake. Ever since new master cyl. I cant figure it out some say the mc has to be bled(?) I took it to a brake guy and he did a test for air but couldnt figure it out either.
jz

[Big D's 69]

Did you bench bleed the master cylinder before you installed it?

[Blue Cloud]

Yeah, I would think air in the system somewhere is the problem. Bled the new MC like the instructions said, and bled the lines 2-3 times, still have to pump up. I just pulled the drums and all looked OK, no brake fluid leaks. There was some gear oil, so went and picked up new seals. Don't think theres a leak in a line or the pedal would go clear to the floor if they pumped up at all. Maybe I got the shoes and hardware on wrong? I don't think so though, but it has been years since I've done a brake job. Does anyone have a scan or a pic of how the rear brakes (dana 60) should look. Maybe my memory left when my hair did?

[SmokeyBear]

Are the shoes adjusted properly? If there is a lot of slack, that might account for it if there is no air in the system?

[Blue Cloud]

I just got them back together, (stopped for lunch). I'll adjust them and test it thes afternoon if it doesnt rain.

[Big D's 69]

Hoefully it all works out for you. Keep us updated.

[flyboy2610]

I have to pump the brakes twice, as well. I have a Dana 60 rear axle. too.

[Blue Cloud]

Well, I got the brakes back together and adjusted them and same thing. Can't seem to figure it out. Could the bleeder valves on the wheel cylinders go bad? I've never heard of that happening but stranger things have occured. Maybe I should change all the lines, kinda scarey driving in traffic this way. Got to be missing something somewhere.

[FORDification]

Bleeder valves might fill up with junk and garbage, but they don't "go bad". If you have to pump the brakes, you've either got a bad MC or air in the lines. I'd say it's air. Yeah, bleeding them out is a major PIA, but it has to be done.

What method are you using for bleeding? Most just have someone inside pumping the pedal and then holding, while you go underneath and crack the bleeder for a second. This method can get the job done, but it'll take a while. You might consider the gravity-bleed method. Just top off the master cylinder and then crack all four bleeders open, and then let gravity take it's course. Just make sure to keep the MC topped off.

Unless your lines are very rusty or leaking, I wouldn't worry too much about them.

[Blue Cloud]

I'll try that on my next off work. If that don't work someone was telling me they had theirs pressured up and bled at a shop, but I hate to pay someone younger than my truck to work on it.

[Blue Cloud]

day

[FORDification]

If you have access to a pressure-bleeder, by all means go that route, even if you have to pay someone a few bucks to get it done. It'll be money well spent, IMO.

[71 LONG BED]

I'll try that on my next off work. If that don't work someone was telling me they had theirs pressured up and bled at a shop, but I hate to pay someone younger than my truck to work on it.