Didn't run master dry... And no major fluid loss. Brake pedal began slipping to floor when stopped at lights and such. Pumping them firmed them up. I been looking for vacuum leaks. There is some fluid showing on brake booster from master cylinder. Not a lot. Been like this a few days. Well today it happened. To the floor .. almost blew a busy intersection but got her stopped. Shop says new master and booster due to age. My question.. I have no exp. With either.. but have bled brakes. Is this something I should even attempt on my own. I dont really have the cash to have shop do it. Also wanted to run by you guys in case shop is bs ing me.

 

It is not that hard to do ...but you need to make sure you bench bleed the new master before you install it...otherwise it will take forever to get all the air out....
Another thing to check is is the rear wheel cylinders as they can seep and cause a simlar effect...You need to remove the drums to determine that however...

 

It was mentioned to me about the new booster needing to be adjusted ... And if not done correctly could puncture and destroy the new one. Any info on that. I am assuming I can find a link in here on bench bleeding master.. so not too worried about that. When I remove the drums.. things will be wet with brake fluid?... also.. wouldn't I have noticeable loss of fluid if rears were leaking? Also how about the system flush.. is that easily done at home also?

 

You do not always notice the fluid seeping with drums on , so removing them you will see fluid if they are bad... and you should be able to flush the system...as far as adjusting the booster push rod that could be possible but I never have done it ...I just left the rod the same...have you checked the Factory Manual ?
I had one but since I have a newer van I think I threw it out.....I do have the one for my truck which is a 76..so I could look it up tomorrow ...Or somebody else might know about your specific model....

 

I don't have any manuals for it... But looks as though I may be buying a Haynes or Chilton very soon. Don't want to get in over my head. Shop didn't remove the rear drums when diagnosing.

 

I found this ....Ask.com - What's Your Question?

 

Didn't even think of using ask.com. I don't have 2 people. Looks like the shop wins this one. I will however ask them to remove rear drums while I am there to check those. I also need to rebuild the carb. And have 0 xlerience there. Ever done it? And is it difficult or tricky? Thanks for the responses.

 

It is almost cheaper to replace the carb nowadays..what carb is on it ?
The biggest thing with carb rebuilding is cleaning it well...You need compressed air too and a few small brushes...I have done it a few times ...Ford carbs are garbage...I like Holleys....Edelbrock makes good carbs too...have you looked here ...http://www.summitracing.com/int/sear...r-rebuild-kits

 

Have done 0 research in carb. This is supposed to be a temp vehicle while I save up for another, so trying hard not to put anything into that I don't have to. If ibwas to replace the carb. I would want to go with something cheap but effective. I do not know what carb is on it.

 

hey Grinder,
I see it's been a little over a week of your posting and assume that you probably have your issues resolved. But if not, here's my 2 cents: The symptoms you described were exactly what happened on my 78 E250, i was lucky and only had to replace the master cylinder, actually the 3rd master cylinder since I've had this van for 26 years. Same symptoms every time. I am running on my original brake booster unit which is 37 years old and has somewhere in the vicinity of 800,00 miles on it. Amazing! Each time I replaced the master cylinder, i did not touch nor adjust the brake booster push rod which is where any adjustment would be required and it was fine each time. Of the 3 master cylinder units I replaced, I only had to pay for the first one, the other 2 were free compliments of life time warranty from 0'reillys. You could have leakage at one or both of the rear brake cylinders, but your symptom description much more appears to be the master cylinder. Hope this is helpful to you.

 

When I approached that green light that turned yellow.... And the pedal no longer pumped up..... But instead went straight to the floor and on came the brake light.... And stop not did van. I did what any other person about to wipe out an intersection full of cars would do.. stood on it tillbi put it throught the firewall, dropped shifter to 1st. And went for the E brake. Got her stopped just on other side of crosswalk. No collision... And e braked it to shop. Master and booster was the claim at 400 parts and labor. No time to debate or second guess it. Thanks for the responses on this.