what size and thread plugs????

[Compu Doc]

What size and thread plugs do I need for a master cylinder for a Ford E350. I need to disconnect the lines coming out of it so I can see if it is bad or if the RABS valve assembly is the culprit for my brake problem.

If you pump the pedal 3-4 times the brakes are ok and he pedal will hold. Anti lock brake light is not on. Neither is the red brake light. Anti lock brakes comes on and goes right off when starting as it is supposed to.

 

[PackRat]

If you pump the pedal 3-4 times the brakes are ok and he pedal will hold.

Following the KISS guidelines, are you certain that the rear brakes are adjusted properly? My 62 Chev does that every now & then. A couple cranks on the star wheel, and all is good again.

Beyond that, it would surely be worth the time, to pll a rear drum, and check out the wear on the rear shoes.

 

[Compu Doc]

Rear shoes and front pads were replaced 2000 miles ago. I's definetly a hydraulic problem and there are no leaks. The fluid level is the same as it has always been.

I had this problem about 3 years ago and took it into a shop to have it fixed. Instead of the mechanic diagnosing the problem they threw parts at it until it was fixed. At that time there was new wheel cylinders installed (that time they were leaking) new shoes and drums. They also insalled a new master cylinder and was having the same problem of the pedal not being right and going to the floor. They then installed a rebuilt RABS valve which cured the problem and submited to me a bill for over $1000.00.

Now I can go out and buy a new MC and another RABS valve but the parts alone would be arouund $300 so instead of throwing parts at it I want to diagnose the problem first so this way I am not spending money on parts I do not need.

As for your 1962 Chevy that does not have a Rear Antilock Brake System. I'm almost also certain that you do not have a dual chamber MC and definitely do not have disk brakes and in fact there probably manual brakes and not power brakes as our trucks have.

Here you will find a good article that describes the problem I am having and how to correctly diagnose it.

 

[highest_vision]

Maybe consider taking some calipers to your line nuts to get the size and going from there. Could be metric, but a parts store might be able to tell you size if you went and asked them and then you would have new nuts to compare. They would probably have standard plugs. Or see if the store has a master for your van and will let you test size with that
Even though you only have 2k on your back brakes, might want to make sure they are still adj up. Seen it happen What's your pedal height?
May be also easier to bypass the rabs valve to test it. Probably could by a pre-flared short length of tube and two unions and bleed the brakes.
James

 

[PackRat]

You didn't mention that you had the shoes/pads replaced recently. I was just offering a simple suggestion, before you tore into the hydraulic system. Personally, I hate bleeding brakes, thus my suggestion.
I am admittedly,not a Ferd man. Just throwing in my 2 cents.

 

[Mr_Roboto]

Please add your truck information to your signature, there were a whole lot of years of E350's made.

I second manually adjusting the rear brakes. I have to do that every couple months in my truck, despite the fact that the self adjusters DO work.

The fact that pumping the brakes makes them work normally indicates that there is either a loose adjustment, or air in the lines. A master or ABS valve will leak internally regardless of how much you pump the brakes.

As for the plugs, as was said above you will need to measure the line nuts and go to the parts store. I know the older vans I had (mid 90's) had inch dimension lines, they may have switched to metric at some point, I don't know. Normally Fords will have 2 different sized line nuts at the master cylinder, this is done to prevent reversal of the lines on the assembly line at the factory.

 

[icanfixall]

Heres what you do. Go to any wrecking yard- pick a part. Find a big ford or merc. car or truck and just remove the parts you need. End nippers or large wire cutters will cut thw line, then soldier up the ends close to the nut and do your test.