I am in the process of resurecting a 49 F6 That I picked up a while back. I got the engine installed and radiator in today, not to mention a new windshield. I am however a little flustered about the brakes. The previus owner said the brakes worked great it was just that you had to bleed them every time you wanted to use it as all the fluid poured out somewhere that he never bothered to locate.

My questions are.......

Is the old midland hydrovac system worth overhauling? It is a single circuit system and seems needlessly complex.

If one were to rebuild it how much would it cost and where does one get parts?

Has anyone ever installed a universal power brake booster on one of these bigger trucks with any success? They seem to cost a lot less and would have the added benefit of dual circuits for more safety.

I know that speedway sells 1 1/8 bore power brakes with booster attached for underfloor installation for under $200 so I am kinda curious if that would work.

Any help here at all would be great.

 

I cant comment on the original system, but an aftermarket system could be adapted. The larger trucks had different brake pedals and mounts, so a direct fit brake kit would most likely have to be modified to fit, but it can be done.

 

I replaced the booster on my 52 F6 a few years ago and learned quite a bit about the brake systems on these beasts that I believe is transferrable to your 49 F6.

First off, the stock brake booster is a Midland C447. There is no rebuild kit available for it and any reputable rebuilder will not attempt to rebuild it for you and instead recommend a near identical upgrade to a Midland C462. I got a new one from NAPA for about $250 or so; NBB 518026 - is a Midland C462C/H and is basically the same as a C447 with the exception of the frame mounting hardware and the vaccume line is not threaded like the C447.

Mounting to the frame is nothing difficult to over come - it's just a matter of drilling another 1/2 inch hole in your existing mount plate. Easy peasy with my electric drill and a sub $20 drill bit.

You can sift through my experience here and I am more than willing to help you out with the stock system

https://www.ford-trucks.com/forums/10...job-parts.html

 

Thank you for the response. No idea if anyone has tried swaping something else in though..........

On your 52 F6 how well do the brakes function? Do you ever haul with it? Also what size bore is your master cylinder?

Thanks very much for the response because even my old guy gurus are a bit foggy with the old hydrovac system...........

 

I use the stock master cylinder with a 1 1/4 bore. Only the small trucks had 1 1/8 bore.

My F6 is actually a fire truck, so I have lots of extra weight with the pump, fire gear etc., My feelings are a well maintained stock brake system works well enough for what it is. Be very aware that most if not all of the aftermarket disc conversions and power conversions etc are for the F1 series and will be unacceptable for your F6, especially if you plan to haul. From what I see, those who don't stick with the stock brakes end up with axles, suspension, and powertrains from 70s trucks or RVs.

Since we are talking about the stock brake system, be ware of the following:

*Drums and Shoes cannot be obtained new.
*Drums can be turned, and due to their scarcity, they can be turned past spec. Some operators even opt for inserts.
*Shoes can be taken to a good brake/clutch shop and relined, sometimes with thicker than spec to make up for over turned drums.
*Master Cylidners and rebuild kits are available from NAPA, RockAuto etc.
*Wheel Cylinders are available through NAPA, RockAuto ect. The F4, F5, and F6 used the same ones.
*The brass brake line manifold on the rear of the master cylinder is not reproduced. You need X-Ray vision to see how it's plumbed:

 

Got it moving under its own power today. Used the hand brake to stop however.

Removed the master and hydrovac unit to get parts..........................
The vacuum diaphragm was full of brake fluid. I mean full!
The lines for the front brakes were disconnected completely, and a line looped around to close off the circuit.
The rear lines broke in two after working them back and forth several times.

So now I need a hydrovac unit and a master cylinder not to mention a roll or two of brake line. I cannot find any number or ID tag on the hydrovac whatsoever. Are you sure that the part you listed is a suitable replacement.

For now I will leave the wheel cylinders alone. Most of my issues I feel are due to age as this thing has less than 35k miles on it.

Thanks for your help so far.

 

Master Cylinders are available. You want the 1 1/4 bore.

My old and new booster:



As for your brake lines, it is likely a blessing you discovered they were weak in this manner rather the alternative...

 

Got a master cylinder and all new hard lines in today and it does stop. Pedal was hard as heck and noticed that she drug a bit while moving. Front shoes are rubbing......
Have to go to Napa and order some wheel cylinders tomorrow. How do I Back off the shoes so I can get the drum off? No star wheel hole that I noticed. Got the wheel bearing loose and tapped around the circumfrence for a bit but to no avail!
I think if I start prying I will mess up my shoes and have to get them relined.
Thanks for the help thus far.

 

If you take a look at the back of the drum backing plate, there are two nuts on the bottom with "dials" protruding from the bolt. These are the shoe adjusters. The dials are marked with a recessed dot. Normal adjustment has these pointing up and inwards towards eachother. The further up, the tighter the adjustment, the more horizontal, the less the adjustment (If my memory serves me correctly). Simply loosen the nuts and adjust the dials to relieve the pressure on the drum.

There is also a nut about 3/4 the way up that is attached to a spiral mechanisim inside the drum for each shoe. This is the fine adjuster, but I find that rarely makes the required difference.

All this is detailed in the shop manuals which you can purchase from your favorite Ford specialty supplier:

http://www.macsautoparts.com/ford_tr...ual-on-cd.html

 

For now, I bypassed my booster. It may come to pass that I want to haul some heavy loads with this thing when it's more complete, and then I will get a new booster. You should read my recent thread here called remote booster bypass. I learned some interesting things about these brakes and shared them in that thread. Good luck and us big truck lovers will be following your progress for sure!

 

Thank you Bmoran, I was kinda figuring that but was not sure. Ordered new wheel cylinders today so hopefuly have them by Friday.
Read your write up GB, I am experiencing the hard pedal thing too but am hoping it is related to the wheel cylinders. I priced new soft hoses from napa as well and found them to be less than $40 for all three! If the cylinders and new hoses do not cure the pedal issue I will look into this plugged valve body situation. I used a reman cylinder so I assume that it is assembled correctly. I did paint it so I should also check the vent on the cap as well.

Thanks again for all your help.

 

When you remove the hoses from the wheel cylinders make sure you save the adapters, you will need them for the new hoses.

 

Went down there tonight to do something and adjusted the brake adjusters to horizontal. Still dragging but not quite so bad. So, My guess is the wheel cylinders. I noticed a dot on a few of the adjusters. What is the correct orientation?

 

Go to this thread, read and understand about the double anchor brake system. The lower adjustment is the primary adjustment followed by the cam adjustments midway on the backing plate. Edit:
Unless the brakes have had recent service, the adjustments may not function as designed.

https://www.ford-trucks.com/forums/1...ttle-shoe.html

 

Well now the brakes work!

I do have to take the time to adjust them but it has no issues stopping. They do feel as if I need to bleed them again though. Just a bit vague and spongey.
So me and my father in law were bumming it around the section line and we figured we would give my 12yr boy a shot driving her...........Wow! The kid can double clutch great and is better at getting a down shift than me!

Cocky kids.

Thanks for the help guys.