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Hydroboost brake conversion

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Blacktop

Re: Hydroboost brake conversion

Using the existing plate would retain the angled mounting to hopefully help with the pedal pin alignment problem, I think🤔

1984 F150 XLT short bed 4x4 351w 4speed manual
1980 F100 long bed 2wd 300-6 3speed manual project truck
🇬🇧UK based truck enthusiast🇬🇧

Gary Lewis

Re: Hydroboost brake conversion

Administrator

You might speak German: Jein. The angle will change where the linkage hits the pedal, but it won't change the lever arm.

In other words, the move of the pin was to change the amount of mechanical advantage as well as the amount of travel. Jonathan previously said:

A lot of F250/350 owners use their existing pedal with no complaints. If they later upgrade to the right pedal, the usual comment is that it has improved pedal feel. However, note that the F250 HD F350 vacuum pedal is different than the light duty vacuum pedal. The pin is higher. I do not know of anyone who has tried to use a half ton vacuum pedal with hydroboost, but I don’t think it would work well. I think the geometry with the rod is too different. The leverage would be even less, resulting in (probably) unacceptable pedal feel. If you can’t find a hydroboost pedal, I would at the very least try to find a HD vacuum pedal, or better yet find a machinist to move the pin. There is a guy on one of the diesel Facebook pages that offers that service.

And changing the angle of the booster does not address the mechanical advantage nor the amount of travel.

Or, did I misunderstand? Are you planning to move the pin?

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

Blacktop

Re: Hydroboost brake conversion

Ahh, I see. Yes I am anticipating having to move the pedal pin.

Alan

1984 F150 XLT short bed 4x4 351w 4speed manual
1980 F100 long bed 2wd 300-6 3speed manual project truck
🇬🇧UK based truck enthusiast🇬🇧

Gary Lewis

Re: Hydroboost brake conversion

Administrator

If you move the pin then you need to consider where the link will hit if you put a flat plate on.

Gary, AKA "Gary fellow": Profile

Blacktop

Re: Hydroboost brake conversion

Interesting write up:
https://classicbroncos.com/hydroboost_cobra.shtml
Mocked up my hydroboost set up today. I will need to make either a new mounting plate or adapt the mustang one I have. I could drill the firewall to suit but I want to keep it as is.
The pedal rod alignment to pin looks really good with the angled mounting bracket but the pedal rod is about an inch too short. I can either mod the existing rod or make an adjustable one to suit.

Alan

1984 F150 XLT short bed 4x4 351w 4speed manual
1980 F100 long bed 2wd 300-6 3speed manual project truck
🇬🇧UK based truck enthusiast🇬🇧

Blacktop

Re: Hydroboost brake conversion

First I tried mounting the plate by referencing the top mounting holes but this placed the hydroboost too low:

By using the lower right hole, it places the bracket much better. I just need to make an adapter plate to go between the two:

I also had to file off the tab to allow the booster to orientate properly. I will weld on a new tab later. Sorry, the pics have rotated 90 degrees again😡

1984 F150 XLT short bed 4x4 351w 4speed manual
1980 F100 long bed 2wd 300-6 3speed manual project truck
🇬🇧UK based truck enthusiast🇬🇧

Blacktop

Re: Hydroboost brake conversion

From the inside, the alignment is close but the push rod is too short, I'll make a longer one. The pic shows the booster at the lower position, it is much better when in the higher position.

1984 F150 XLT short bed 4x4 351w 4speed manual
1980 F100 long bed 2wd 300-6 3speed manual project truck
🇬🇧UK based truck enthusiast🇬🇧

Blacktop

Re: Hydroboost brake conversion

Once the mounting bracket is done, I'll make a new push rod to suit using this spare:

1984 F150 XLT short bed 4x4 351w 4speed manual
1980 F100 long bed 2wd 300-6 3speed manual project truck
🇬🇧UK based truck enthusiast🇬🇧

Gary Lewis

Re: Hydroboost brake conversion

Administrator

That's a good writeup you found. Thanks!

And, you are making good progress. So you aren't going to move the pin? It looks like it is in a good spot for the rod, so you'll try it there? I hope it works well.

Keep on keeping on!

Gary, AKA "Gary fellow": Profile

Blacktop

Re: Hydroboost brake conversion

Yes Gary, hoping to not have to move the pedal pin. Although I will if I find I have to👍.
Only thing that puzzles me on that write up, why he didnt orientate the mounting bracket vertically rather than horizontally. He wouldnt have needed to bend the pedal rod if he had!?!

1984 F150 XLT short bed 4x4 351w 4speed manual
1980 F100 long bed 2wd 300-6 3speed manual project truck
🇬🇧UK based truck enthusiast🇬🇧

Gary Lewis

Re: Hydroboost brake conversion

Administrator

I think he had a clearance problem.

Anyway, let us know how it goes, please.

Gary, AKA "Gary fellow": Profile

Blacktop

Re: Hydroboost brake conversion

Made a simple puller to remove the pedal rod from the booster, worked a treat👍

1984 F150 XLT short bed 4x4 351w 4speed manual
1980 F100 long bed 2wd 300-6 3speed manual project truck
🇬🇧UK based truck enthusiast🇬🇧

Gary Lewis

Re: Hydroboost brake conversion

Administrator

I wondered how to do that. Well done!

Did you say you are going to make a new one? Will it be adjustable?

Gary, AKA "Gary fellow": Profile

Blacktop

Re: Hydroboost brake conversion

Yeah, thats the plan👍.

1984 F150 XLT short bed 4x4 351w 4speed manual
1980 F100 long bed 2wd 300-6 3speed manual project truck
🇬🇧UK based truck enthusiast🇬🇧

Bruce moose4x4

Re: Hydroboost brake conversion

In reply to this post by Gary Lewis

They do have this available.
https://www.summitracing.com/parts/wil-330-13914
Adjustable rod kit.

Bruce aka Moose--1978 F250 LWB Flareside, Dana 60's w/ 4:10's, 460, c6

Blacktop

Re: Hydroboost brake conversion

Overall cost would be too much to ship to me in the UK. I’ll just make something myself but thanks for the suggestion 👍

1984 F150 XLT short bed 4x4 351w 4speed manual
1980 F100 long bed 2wd 300-6 3speed manual project truck
🇬🇧UK based truck enthusiast🇬🇧

Gary Lewis

Re: Hydroboost brake conversion

Administrator

Blacktop wrote

Overall cost would be too much to ship to me in the UK. I’ll just make something myself but thanks for the suggestion 👍

I remember where you are, usually, but might it help if you mentioned that in your signature?

Gary, AKA "Gary fellow": Profile

Blacktop

Re: Hydroboost brake conversion

Ahh yes, good idea👍

1984 F150 XLT short bed 4x4 351w 4speed manual
1980 F100 long bed 2wd 300-6 3speed manual project truck
🇬🇧UK based truck enthusiast🇬🇧

Gary Lewis

Re: Hydroboost brake conversion

Administrator

Well done.

I noticed that you included Great Britain awa the United Kingdom. And I wanted to ask if that was perhaps due to the possibility of Ireland and Scotland leaving the UK due to Brexit. But, that could get into politics, so I won't.

Gary, AKA "Gary fellow": Profile

Blacktop

Re: Hydroboost brake conversion

Haha, best not to get involved in politics.

Push rod modified. Made it longer than needed incase I need to trim the length👍

1984 F150 XLT short bed 4x4 351w 4speed manual
1980 F100 long bed 2wd 300-6 3speed manual project truck
🇬🇧UK based truck enthusiast🇬🇧

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