Thanks, does anyone have any suggestions on where to find a couple of residual valves. Napa maybe? Hate to have to order them and pay the shipping.

 

I think they might come as part of the MC. Take a look at your MC, is there what looks like a fitting adapter screwed into one of the outlets? If so, I think that is the residual valve.
I don't know if the local parts stores might have something or not. Wrecking yard?

Bobby

 

On the Mustang type MC's, if you look inside the port behind the flare seat, you'll see a little spindle if there is a RPV installed. You can carefully push it in to confirm. The advantages I see to a MC-installed RPV is it takes up no space, and two less joints to leak.

 

Thanks for the comments, I agree from what I have read on-line from others dealing with similar issues.

Let me ask this....can anyone tell me when and if Ford used a Master cylinder after 1952 with the 1.5 bore size ( or above ) preferably that will bolt onto my 1986 F-250 ( actually I plan to replace the 250 booster with a 350 booster since it will take up less space, is a dual diaphragm and will still from what I have found bolt directly onto my 86 pedal assy )

I have read for instance on-line that a 2005 F-350 used a bore size of 1.5 and a 99 F-350 carried a bore size of 1 5/8. I would bet that in this case a bit bigger would be better. I would prefer if possible to find a piston bore diam the same size or bigger that what was originally in my truck because it just makes sense that they matched the MC bore size with the wheel cylinder bore size.

Kicker is though is I do not know whether or not either of these MC will bolt onto either of my intended brake boosters. I guess it may come down to up-setting the Napa man by going thru his stock just to see what fits.

I dont know why but 2 5/8 spacing on my booster comes to mind and from what I have read Ford used this spacing as standard for many years but I do not know if that bit of info is relevant when considering the larger trucks I.E larger bore sizes. HELP!

This thread I guess may be getting confusing so I may move this post at least as a new topic.

 

Just for someone future reference ( I have found past posts within this forum to be great help so hopefully by continuing this thread I will be helping someone in the future with similar problems ) that a 1980 C-60 GMC carried a 1.5 inch bore. Problem though is that it will not bolt onto my master and I really would prefer to stay away from non Ford parts on my truck not that anything wrong with that and if push comes to shove Ill be mounting a GEO master if that does what I need it to do and its my only option.

My point to adding this is that other makes are available that may work to get someone down the road.

 

Thanks, I looked into these Mustang masters but the bore sizes seem to have stopped for all year mustangs or rather capped out at 1 1/16 if Im not mistaken.

This is pretty much what I have in the truck now and need a bigger size.

I want this to be the last time I have to screw with these brakes.

I am still getting shrills over the possibility of not sending out my wheel cylinders for re-building but as mentioned if they did not leak fluid than I guess there really is no issue with them.

I am going to have to remove them all at least once more and give them a light honing, the truck has been sitting again maybe close to two years since the last time I messed with it and I can see a light coat of rust on the insides of at least the one I have already pulled.

Knowing my luck this light hone I plan to do will put them over the top though and they are gonna leak live a sieve.

I guess I have decided though that worse case scenario I should have them rebuilt rather than buy the NOS cylinders that are available.

If the NOS ones are 90 bucks a piece and to have my old ones re-lined with SS is 90 bucks than I would be better off having them re-lined since it will be the last time I will have to worry about them.

If there was an advantage such as a bit of a price break on the NOS ones than I would go that route but I just cant stomach the thought of not long ago being able to buy these cylinders from Napa for less than half of what is being asked now.

 

one of the problems that I and probably everyone els here has experienced, is that when you have to by parts for our older trucks once you get into the biger fords, is that the parts shop do not have good old cross reference books any longer. Right now, there is one guy at our local NAPA that is old school, ( 32 years) and can really find stuff for me. How ever, NAPA is not cheap by any means. Even when I give him a ford number, that perhaps Number Dummy was kind enough to look up for me, sometimes, he can no longer do anything with that number.

 

Old man Big Job now confused. A 52 F7 Whats wrong with the way It
suppost to be. First off Ford did not make this. 1.500 bore to fit a
Ford truck? I think not being wise guy you have to do some more
research. I just went through this whole thing on a Trojan loader,
same identical master cyl. I went through my boxes of cyl. both
1.5 to 1.750 bores (old used ones) . No. 2 the residual valve is not
in the master cyl it is in the booster. Napa booster for your truck is
about $150 from Napa and thats the same one in my loader. No 3
48 thru 52 trucks are not probmactic to bleeding, every hydraulic
system is a nightmare. No4 I am not a hobbist I run a machine shop
and repair. Six trucks in two weeks, brake lines brake lines, seems
all the 1990's are taking a dump and then deal with abs. And then the
old "as time" first pump to the floor second pump it come up, then you
got Air bro. Finnally No5 all said and done correct that F7 will put you
thru the windshied and also fooling with F250 M cyl. is fooling with
displacements that wont work. Myself id put back what belongs there.

 

Big Job,

OMG, what beautiful trucks. Wish I could see them in person

JimG 1098

 

He's right - with hydrovac booster and stock MC, residual valve is removed from end of MC and there is one in the booster instead.

 

I do not have any of the original braking system, no pedal assy, nuthin, some of it came in boxes but all of it was junk and too many missing parts.

Whats done is done and I need to keep plugging at it the way I am going.

 

I have used a disk master cyl on a drum system by adding a 10 lb residual valve. Summit or Speedway are a good souce for these valves , they are inexpensive and will solve your problem. Does your rear feed the brakes from the top and bleed on the bottom wheel cyl ? My 57 F600 was this way and was a pain to bleed , I swapped the feed to the bottom and bleeder to the top , this solved some of my bleeding problems. I have swapped several large trucks from hydrovac to hydraulic booster , many IH school busses use the hydraulic booster system but have discs front and rear. Using this system on a drum brake truck requires residual valves front and rear, this makes a very reliable and dependable system.

Just some Thoughts-- -- -- Hotwrench

 

I was not sure how they were originally fed but yes I have upper and lower wheel cylinders. I guess from what you say it would make more sense to feed the bottom instead of the top. I have a bleeder on both wheel cylinders though top and bottom. Do you have this as well?

I am planing on getting this residual valve, I have been told to put one in the front line that feeds the front brakes and one in the rear line, I have read they make a 12 pounder, maybe they make even higher, I do not know. I wonder if it would be any advantage to getting one a bit higher since the springs on these things are beefy?

 

A 10 lb valve is considered enough. Origionaly mine fed the top wheel cylinder and had a jumper line to the lower wheel cyl and this one had the bleeder on it. When I rebuilt the brakes I fed fluid to the bottom and bleed the top , this simplified the bleeding process. Mine only had bleeders on one cyl per side.

Have A Great Day ------- Hotwrench

 

Thanks, seeing how my truck was sorta tossed together its tough to say how it originally was set-up, I will look in manual and see if there is a pic