Hydroboost install question

[Ironman03R]

The truck has gone under the knife to get ready for the rally!

I'm using a hydrobooster form a 94 F450 to put on my 94 F350. I have the booster mounted and stock pedal attached and it seems to work fine, no binding, but its angled slightly downward. There seems to be a lot of up and down movement avalable in the pushrod, it piviots. Do I really need to move the ataching point on the pedal?
I would have used the pedal from the doner truck but its for a 5-speed.
What angle am I tryin to get on the pushrod? Should it be completly level?

 

[Exekiel69]

Should it be completly level?

That is ideal. I had to move mine a little.

 

[Dsl_Dog_Treat]

Steve, that sounds bout right. Bolt on application.
A little play is good.
Where one gets into trouble is when the pushrod binds up on the housing of the MC.

 

[GRU]

i havent swapped pedals on mine yet. it gives it an incredibly hard pedal since its moving the rod more per pedal travel since the pin is lower. id like to change it for more pedal travel.

 

[Dsl_Dog_Treat]

i havent swapped pedals on mine yet. it gives it an incredibly hard pedal since its moving the rod more per pedal travel since the pin is lower. id like to change it for more pedal travel.

On the 89 you shouldn't have to swap pedals.
There should be hard pedal yes, but very minimal pedal travel.

 

[icanfixall]

When I did my hydroboost I used the F450 peddle with the 1 5/16 master cylinder and the feel is great. Very little movement of the peddle and the brakes are working. Remember you are doubleing the line pressure when you do this modification. The stock vacuum brakes have around 1100 lbs of advantage and the hydroboost has around 2200 lbs.

 

[MIDNIGHT RIDER]

From what models of truck do I need to shop for a hydro-boost that is easiest/best for my 1985 F-350 ??

Thanks.

 

[snicklas]

I am not 100% sure..... but I think the OBS F-Super Duty (450) is the easiest. Get the pedal and the booster, some people even swipe the Power Steering pump since it has a bigger reservoir and a place for the return line.

I know on my Ex (3/4 Ton Super Duty chassis) I love the hydroboost brakes. It has 4 wheel disk and hydroboost, and it will stop RIGHT NOW!!!!. I can stop my Ex and 4500lb TT with the trailer brakes turned off better that I could stop just my older E-150 and F-150's empty......

I can see it would be well worth the work........

 

[GRU]

see now i went through a whole buttload of work getting the disc brake swap and hydroboost on mine and im not very happy. my brand new rotors in the back (i think, havent checked yet) warped almost instantly. it will lock em down easily empty but when i was hauling dirt the other day and my trailer connection went bad it would hardly slow the rig down withoutout really planning the stop way in advance. thats why im thinking i need to move my pin up to get a bit more pedal leverage. that and i know theres a brakeline thats just waiting to blow. its in very bad shape so im really scared to mash the pedal down.

 

[Dsl_Dog_Treat]

If you have a lot of pedal travel with the hydroboost unit, I'de be looking at either air in the line psoobly from the conversion or you have a bad mater cylinder.
The pedal assembly on my 90 is the same as your 89 and I don't get more than an inch of pedal travel.

I was able to to a quick stop pedal mash on it with a 6900# fiver with no trailer brakes and it stopped fine to where I felt safe.

 

[Ironman03R]

The manual pedal from the doner truck has 2.25" from the botom of the piviot to center of the brake "pin". My truck has about 3". I have an Auto pedal from an 86 and its around 3.5". I'm gonna take it out and drill a new hole unless somone has one floating around.
I also have a problem with the pressure line, the teflon seal tore when it came out, where can I get a new one? Can I just put an O-ring on it?

 

[trackspeeder]

From what models of truck do I need to shop for a hydro-boost that is easiest/best for my 1985 F-350 ??

Thanks.

You can use any F Superduty parts up to 97.

 

[Agnem]

or you have a bad mater cylinder....

You got a patent on that name?




My concern about not moving the pin, would be that over time, the piston being pushed at an angle instead of streight will cause it to wear funny or worse yet, eventually hang up. It might work now.... but what about 50,000 miles from now?

 

[Exekiel69]

My concern about not moving the pin, would be that over time, the piston being pushed at an angle instead of streight will cause it to wear funny or worse yet, eventually hang up. It might work now.... but what about 50,000 miles from now?

Exactly.

 

[Ironman03R]

I measured the hydro pedal from the manual truck and drilled and welded mine in the same spot. I had to bend the shift linkage bracket a bit for brake light switch clearance, I'm noticing the pedal is higher than it was before...Almost too high, is this normal?
Other than that this project is done, just need to get some fluid for it. Now on to the heated tank and L/S diff.