Thinking of Converting to Hydroboost brakes.

[79K30_89C7000]

My 1979 K20/30's brakes leave a little bit to be desired especially since ruck constantly weighs over 9000lbs. It used to be a 3/4 ton until I swapped the Dana 44 front a 14 bolt rear for a Dana 60 front and Dana 70HD rear 3 years ago. I had converted to full disc brakes before the axle swap and the brakes still weren't as good as I had hoped. Then after the swap I was back to disc fronts and drum rears. We put my 3/4 ton axles including the 14 bolt with disc's under my brothers 78 crewcab that had hydroboost and that truck stops like a dream. My brakes system is up to snuff on my '79 but I'm still not satisfied. I have a Hydroboost system with lines a everything that I'm probably going to install on my K20/30. I had a '89 GMC C7000 with a 8.2 Detroit Diesel that was my welding rig for awhile and it had hydroboost on it and it stopped like a dream to. It had 4 wheel disc's too. Eventually I would like to convert my rear drums on my Dana 70HD to disc's. I was just going to get some opinions a see if switching to hydroboost was going to gain me much.


My '79 K20/30 with vaccum style brakes


Brothers '78 K30/20 with hydroboost


My old '89 C7000 with hydroboost


The time I needed alot more brakes. Weighed 27,000lbs at the grain elevator scales.

[VileZambonie]

Probably not, Is the vacuum booster working correctly? I assume you already verified all of your brakes are in proper working order. Are you using the correct combination valve?

[79K30_89C7000]

Yeah I've been through my entire brake system and everything seems to work as it should. I just want better. Probably the only way to get better brakes is to convert to rear discs.

[eventhorizon66]

I converted to hydroboost brakes in combination with a 1.25" piston MC.  I can definitely say my braking feel has improved.  I can "threshold" brake much more easily now and the feel is very responsive and consistent (the exact opposite of what it was before).  I could easily lock my brakes up before the swap, so there was nothing to be gained in terms of usable braking power, but I feel my stopping distances have improved nonetheless due to the dramatically improved responsiveness.  I made the swap in the first place when I was planning to run a big-cam motor, and if I had known at the time that I would end up with a stock 350, I would have probably kept the vacuum booster.  But now that I have hydroboost, I love it and I'm not sorry I ended up with a system that I don't necessarily need.

Notice that I said I also swapped over to a larger MC.  Stock MC piston is 1" I believe, and simply bolting a 1.25" onto the vacuum booster would have likely resulted to an overly touchy and stiff pedal.  But with the additional assist of the hydroboost, it works like a champ.  Not too stiff, not too soft.  Now if only I had the traction to put all this additional braking power to use.  Time for some 275/60-15's all around.

[exilous]

not to stray completely off the topic of braking systems but i like your 79 rig man its sweet. those tires look real agressive what kind are they?

[79K30_89C7000]

I think what I am really wanting is more responsivness as well. I can lock them up if need be. I tested that good one night going to work when a 700lb black heifer appeared in front of me. I laid black marks all the way around and still hit her. My Brothers crewcab with the hydroboost is very responsive and so was my 89 C7000.

Those tires are 36x12.50 16.5's Goodyear Wrangler Military OZ's. Great tire for what I do except I can't find new surplus ones anymore and I don't know what I'm gonna do after this set wears out. They were only $100 a piece including shipping from Pennsylvannia to Missouri. A comparable tire is going to be over $200 closer to $300 now.