I swapped a HP dana 60 in my 1975 F-250 crew cab 4x4. Everything went well until it was time to bleed the brakes. Rears were fine but could not get any fluid out of the fronts.
I swapped the whole system from the donor truck which was a 1978. The booster, mc, proportioning valve and lines. Everything was working on the donor but it sat for a couple of years.
I read on here about bleeding the proportioning valve to get the fluid to the front. I was able to pull the bleeder rod on the front but this did not seem to help.
I don't think the mc would need to be bled as I never removed the lines to it or the proportioning valve.
Does the bleeder rod center the main pin in the proportioning valve. I read that this moves to isolate the front or rear in case of a leak but then read that was only done in the mc. Would the rod sticking one way or the other block the fluid from entering the front even when the bleeder rod is pulled?
I have seen two different types of bleeding tools and assume using both may solve my problem. One is the little metal clip to pull out the bleeder rod and the other screws in the brake light warning sensor hole and blocks the main pin from moving.
Proportioning Valve Tool / Pro Valve Tool-Broncograveyard.com


Any other ideas? Would the proportioning valve be bad?

 

Break the front lines loose at the proportioning valve and press the brake pedal, see if any fluid comes out. If none comes out, retighten the lines and then break it loose on the MC side of the prop valve and press the pedal again. If fluid comes out I would say the prop valve is bad. If no fluid comes out, probably a bad MC.

 

I thought 250/350 required pushing pin in, not pulling. the 150 you pull.
I could look in the manual to confirm but it's easier to guess.

 

I did try both ways with the pin. It pulled out easily about a 1/4 inch. It would not seem to push in. I thought I read that it depended on vehicle weight for the F-250s.

 

Here, and yes you have to find out how far (if any), the fluid is moving from the m/s and down the line to the pro valve and then to each caliper. The pro valve floating pin might be stuck? Thanks for the JBG product lead, I have never seen that one.

 

I'm bringing back this old thread because it's already got the pics/info I need to start.

I've read online that if you do a REAR disc brake swap for a Dana 60, you need to modify the proportioning valve (how it functions) in order to have all 4 brakes applied at once.

This would make sense since the metering valve applied pressure to the front brakes only when the rear drums have "started" their brake application. In essence, the rear drums get pressure first, then the front brakes kick in so that the system acts as a whole because drums move/act much slower than disc brakes do.

So my question...

What's the procedure for eliminating/modifying the application of the metering valve?

I now have a 4-disc brake system on my 1979 4x4 F250, so all 4 calipers should be applied at the same time.


EDIT:

Here is one of the threads I've been reading up on: http://fordification.com/forum/viewtopic.php?t=75384 (post #10, half way down the page). Not sure if it's the same "Ultraranger" on this forum or not.

I don't have a manual proportioning valve installed on the F250 just yet because I don't have my hydroboost conversion complete (intended to do it in the future).

However, fully functioning 4-wheel disc brakes are a must... hydroboost or not... So what needs to be done to the metering valve in the OEM proportioning valve?

 

Get an aftermarket proportioning valve for 4 disc setup. I have an SBC adjustable one

 

Do you have a part number? A reference number or some pictures/more info?

 

https://www.summitracing.com/parts/ssb-a0730pl

This is what I have but there are alot of different option at the link

 

Very cool. Never knew anyone sold something like this. I guess brake modifications are catching on haha.

So how did you wire up the brake idiot light? Looks like a specialty electrical fitting at the distribution block.

 

You dont need it as our brake lights are on the brake pedal

 

Sorry, not the brake light switch. Poor use of words on my part. I meant the idiot light for the brakes when there's a pressure differential between front/rear. It illuminates to let you know something is wrong.

How did you wire yours up to the SSBC unit?