K5 Diesel to Vac booster pedal spring?

[Tja1161]

I converted my K5 6.2 to a gas engine and swap in a power booster set up. I had to buy a diesel pedal and assumed the spring originally had to go on the power brake pedal. I have a lot of travel with spring on and am wondering if I need the spring? Thanks in advance for the help

 

[RoryH19]

If I recall, diesels come with hydroboost not vacuum assist. Did you convert the hydroboost when you swapped the engine? Brake pedal setup will be different between gas and diesel too. I have a gas powered k5 if you need a pic.

 

[Craig 85]

To add to RoryH19's comment, I believe the hole for the push rod on the brake pedal shaft is in a different location than the hydro-boost. I recall seeing a thread on here a while back when someone converted from vacuum to hydro.

 

[Tja1161]

Sorry if my post was confusing. Yes, the pedals are different. My K5 was originally a diesel with hydro-boost. I bought a gas brake pedal from a member here when I converted to vac assist.
My question is do the gas trucks have a brake pedal spring like the diesel? I only see a spring in the manual for JB8 diesel brakes. I put the spring on but I am wondering if I needed it as the brake pedal travel is huge before the brakes engage.

Thanks

 

[bucket]

I believe the spring is only for the hydroboost pedal. I don't recall a spring on any of my vacuum brake pedals.

 

[Tja1161]

Thanks. Maybe i will take it off and see what it does. However, I seem to recall it was pain to install. Thanks

 

[custodian]

I too changed from hydroboost to vacuum boost. I haven't changed my brake pedal yet. There is a difference. I took pics of the pedal on my 73 and compared it to my 85.

The picture on the left is from the 73, it originally had manual brakes that I converted to power brakes, the picture on the right is from the 85, that is originally hydroboost. See the difference where the push rod mounts?

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[custodian]

If I recall, diesels come with hydroboost not vacuum assist. Did you convert the hydroboost when you swapped the engine? Brake pedal setup will be different between gas and diesel too. I have a gas powered k5 if you need a pic.

Could you post a pic of your setup? I too switched from hydroboost to vacuum boost and looking for the right brake pedal.

 

[Tja1161]

See post #2 for side by side of pedals

https://www.gmsquarebody.com/threads/brake-pedal-switch-bracket.23268/

 

[custodian]

See post #2 for side by side of pedals

https://www.gmsquarebody.com/threads/brake-pedal-switch-bracket.23268/

I looked at that thread. So the only real difference is where the push rod and the brake light/cruise control switch bracket mounts?

What I'm seeing is that the hydroboost pedal would push the power booster push rod further than needed? I'm I correct on this?

I bought one from a C30 with power brakes and AT today. Going to take the hydroboost pedal out and compare them.