Hydroboost Linkage to pedal rod

[6600DURAMAX]

Does anyone see an issue with using a clevis style attachment at the hydroboost end? I'm questioning if this will provide or allow too much movement in the pedal rod? I'm having a hard time figuring this out since I am worried about welding that connection due to the heat it could put on the hydroboost rod and into the unit..... I'm probably overthinking this

thoughts

[LockDoc]

Originally Posted by 6600DURAMAX

Does anyone see an issue with using a clevis style attachment at the hydroboost end? I'm questioning if this will provide or allow too much movement in the pedal rod? I'm having a hard time figuring this out since I am worried about welding that connection due to the heat it could put on the hydroboost rod and into the unit..... I'm probably overthinking this

thoughts

I was just working on mine today. I need 1 1/2" added to mine. I don't think I would do that. It might buckle in the middle if you hit the brakes hard. I read a thread the other day where the guy pulled the rod out of the hydroboost, lengthened it and tapped it back into the socket. I think it pulls out pretty hard though. I think a guy could weld it if he had the unit out and wrapped a cold wet rag around it up by the nose where the rod connects. I was going to use a 1/8" thick steel sleeve and drill holes in it so it could be spot welded in the holes. That way you could let it cool between each spot weld. The pressure on it is only compression so that should work OK.

Let me know what you decide to do.

LockDoc

[6600DURAMAX]

LokDoc - thanks for the feedback - I remember reading a post a few days ago that stated that removal of the rod was only possible with an entire tear down of the unit.

Another option was to cut off the "eye" on the hydroboost rod then thread it - but it appears to be smaller than the factory brake pedal rod so a coupler with threaded rod would work either.

I am also considering welding - was thinking of taking it down to my local metal shop and getting some professional welding done vs what I could do. They might have some suggestions as well.

Agree - I need like 1-1/2'' or so as well

[Getter-Done]

I am looking at this and thinking?

You can use an Aluminum block maybe 1.25/1.5 square and 3 or 4 inches long.

Drill a hole in (the pedal end of) this block to thread a stud to attach the clevis and incorporate the use of a jam nut for final adjustment.

Then machine a slot to accept the hydro boost rod.
Taking in account the total distance of pedal height.
Then once the location and diameter of the end of the hydro boost rod are located.
Make or purchase a bronze bushing in this location in the side of the block.

This block will be a solid push on the master cylinder.

D

[Richard]

The rod that came on my hydroboost unit was to short by about an inch. Rather than trying to find one that would work or cobble something together that may be dangerous I just moved the mounting point on the pedal arm. Added material to the back of the arm and drilled a new hole. More material could be added if the push rod is shorter. Included a pic. Sorry for the bad angle.

[Willie Makeit]

what did the hydroboost originally come out of? The one I used was threaded on the end and didn't have the loop. Best that I can remember it was for an Astro Van but not 100% sure on that.

[6600DURAMAX]

After staring at it some more I am considering cutting off the round eye on the hydro-boost side then threading the rod - once threaded just add a simple adjustable turnbuckle/sleeve.

I need to figure out what thread size would work with the given diameter of the existing rod

[6600DURAMAX]

Originally Posted by Willie Makeit

what did the hydroboost originally come out of? The one I used was threaded on the end and didn't have the loop. Best that I can remember it was for an Astro Van but not 100% sure on that.

Its a new unit but would have been on a mid 2000's HD 2500

[1971Stepside]

I did something similar to what Richard did. I took a GM pin out of Tahoe brake pedal and welded it in the back of my truck brake pedal. My idea was that if the booster ever needed replace I didn't want to go with a whole new fabrication process (in case my boys own my truck then). This allowed the factory pedal rod to connect to the brake pedal like it did in the late model Tahoe.

[1971Stepside]

Here are a couple pics of what I did.

[LockDoc]

Originally Posted by Willie Makeit

what did the hydroboost originally come out of? The one I used was threaded on the end and didn't have the loop. Best that I can remember it was for an Astro Van but not 100% sure on that.

Mine is out of a 2001 Chevy 3500 Van, Disk/drum unit. It has a flat mounting plate with 4 bolts in it.

My installation in my '71 Dually pickup starts with post #284 in my build thread.

http://67-72chevytrucks.com/vboard/s...829820&page=12

I am still working on it.

LockDoc

[6600DURAMAX]

I do like the idea of adding to the back side of the brake pedal to alleviate a hodge podge connection points.....

I'll need to stick it back in and see how much material would need to be added

[6600DURAMAX]

Ya looking at it - I believe that adding material to the pedal wouldn't really work as it would be quite a bit. I didn't mount mine flush as I didn't do enough pre prep before truck went to bodyshop.

[fun in dirt]

Just cut & weld length needed onto the rod. We did this 10years ago w hydroboost conversion on my Blazer & have never had an issue with it (same setup in my truck now).
If it makes you nervous about the heat transfer, just tack it & let cool (or wrap a cold, wet towel around that end to absorb some of the heat).

[jeffahart]

Originally Posted by 6600DURAMAX

Does anyone see an issue with using a clevis style attachment at the hydroboost end? I'm questioning if this will provide or allow too much movement in the pedal rod? I'm having a hard time figuring this out since I am worried about welding that connection due to the heat it could put on the hydroboost rod and into the unit..... I'm probably overthinking this

thoughts

I think it would be fine if you machine it to tight tolerances and use good bronze impregnated bushings. Else, it will be sloppy and one more source of rattling to contend with.

I would not weld any part of it yourself unless you know the materials and what you're doing.

I am a fan of the pedal modification. Do it once and never contend with the rod again. You might pop that pedal assembly back in and double check if you can make it work.

Good luck, the hydroboost is a fun easy mod... once you get the rod issue settled.


j

[Willie Makeit]

Just popping back in to correct myself. Mine did have have the loop originally but after crawling under the dash and taking a peep, it appears I cut the loop off and used a die to cut the 3/8-24 threads on it. I then made my own linkage from the hydroboost stem to the pedal using round chromoly thick wall tubing and a small Heim joint with a jamb nut.

[Richard]

Tape a popsicle stick or something else to the pedal to simulate a mounting point and check if it will work. While the mounting point may move up and down a bit more the farther it gets from the arm. The rod has a pivot so that movement may not matter. To me it looks like the adapter bracket for hydroboost could be eliminated. If bottom holes are slightly off just oval a bit and use washers on inside or redrill holes in unit if farther off. My hydroboost from Vanco bolted right on firewall with a slight trim for the column bracket.

[Rickysnickers]

Flipped

[57taskforce]

Mine is welded as well, 3 years on the road and no issues at all. I didn’t even worry about trying to cool it. By the time the heat travels to the associated important parts of the booster it’s likely already below the operating temp that the booster sees anyway. Mine has the captain fab mounting plate similar to what you’ve got above.

[Joyridin]

I cut the hydro rod and threaded it. Then took a bolt and screwed it into the piece that mounts on the pedal. I drilled and tapped the bolt to match the threads I made on the rod. Works good.

[Richard]

A couple of pics of unit mounted flush to firewall. Top holes lined up, two holes drilled for lower bolts and another for the top column mount bolt. As mentioned, a slight notch for the column bracket. Looks like the lower hole on my unit lines up with your adapter bracket. No reason this slight modification could not be done after paint and eliminate the added length on push rod.