Lets talk Hydro boost vs vacuume boost

[oneluckypops]

Curiouse to fine out if tis worth the time to try to sell a hydro boost system. Or is there any real advantages to them?

My thoughts would be it would be a good upgrade for heavy duty towing, and also those that like to run the radical cams causing low vacuume for there booster.

What you all think?

 

[HotRodPC]

I personally have never had a problem towing a trailer with a gross weight of 10,000 + with vac boosted brakes. Granted, the trailer has dual axles and had it's own E brakes on one axle too as a helper. Some consider Hydro boost an upgrade, I don't. More hoses to leak and the hydro boost system itself is expensive as hell when it needs replaced. In fact, one truck I did convert to Vac boost for $15 for a used booster when the hydro boost was leaking badly and it was going to be $300 to replace. The truck stopped on a dime after the conversion to Vac Boost.

I do see that advantage though if you're running power steering anyway, to have hydro boost brakes on a vehicle with a big cam and loss of vacuum. That's about the only reason I'd care to use hydro boost due to it's cost and potential leaks. JMO

 

[bucket]

Besides potential leaks, hydroboost works great for a truck with big brakes and a big master cylinder. Never a squishy feeling brake pedal and a lot of power assist.

 

[oneluckypops]

Besides potential leaks, hydroboost works great for a truck with big brakes and a big master cylinder. Never a squishy feeling brake pedal and a lot of power assist.

that was kind of my thoughts aswell. My K30 is the first truck ive ever owed that has had the hydro boost, and my pedal is TIIIGHT as hell.

Ive got a complete setup off the chasis I just bought I am torn between selling it or using it on my 96 IF I could make it work. Ive got all the hoses, pump, and booster. Decisions Decisions.

 

[HotRodPC]

My K10 that was originally 6.2 still has the Hydroboost on it. I've considered using it on whichever FoBuhFo I make the 3/4 conversion, cuz I might want to go with a big cam in it. Not sure yet, I know I don't need a ton of hp with the low gear I'll be running. Not a mud racer, so money is better spent in traction and axles than a motor IMO for a wheeler truck.

 

[skysurfer]

Hydroboost systems put out around 2400 psi of pressure vs. vacuum brakes' 900 psi. It doesn't matter if you have a modded engine or not, your truck will be easier to stop with 2 1/2 times the clamping pressure at your disposal. There was no way I could lock up the tires with the oem vacuum brakes, even with two feet on the pedal and a good dose of adrenaline when traffic caught me off guard. I had some exciting moments as the bumpers of the stopped cars in front of me disappeared below my hood.

I got a used hydroboost from craigslist for $20. Did the swap but the booster started leaking fluid from the pushrod seal into the cab. It still turned out to be a good deal though because the core was worth $60 when I went and bought a reman unit with a lifetime warranty. All the other bits were picked out of the junkyard. The hoses came from an 80's 1-ton service truck, power steering pump from a GMT 400 Suburban (I wanted the factory return port), and the brake pedal came from a diesel K5. As I remember, the whole swap ended up being around $200-250. That's way cheaper than paying for a collision and having my rates get jacked up. The guy at the yard said he used to sell every hydroboost that came in but there's not much demand for them anymore so you might have to be patient Pops.

The only other thing I did was adjust the load sensing valve located over the rear axle. The rears were locking up too soon which required me to reset the valve, now the front brakes lock first and keep the truck straight in a panic stop.

So was the swap worth it? Oh hell yes.

 

[HotRodPC]

Huhh, so wait??? There's a different pedal for Hydroboost???

 

[skysurfer]

Yep, the pin that the pushrod attaches to is in a different position. I thought changing the pedal was going to be a pain but it was much easier than I expected.

 

[jake wells]

the hydroboost is more sensitive on my truck when for the first few miles of driving due to the old thick power steering fluid. but yes i have locked it up before due to some idiot. and i have locked the brakes on a truck with vacuum boosters.

 

[HotRodPC]

Yep, the pin that the pushrod attaches to is in a different position. I thought changing the pedal was going to be a pain but it was much easier than I expected.

I know on that 80 GMC 1/2 Ton Diesel, I converted to Vac Boost because I was uncertain what I was doing with the truck for sure at that point. Vac Boost was high dollar to replace, and Vac Booster at Pul A Part was $15 so I found a really nice clean shiney one that appeared to be relatively new, and it installed fine. using all the same hardware. I did use the push rod from the Vac Booster though because I thought there could be a length difference.

Maybe it was because the hydroboost was more defective than I realized, I thought it only leaked, but honestly, I had a much firmer, more sensative pedal with the Vac Boost. Seemed the hydro boost let the pedal travel further which didn't make sense to me. I figured the master cylinder would determine how far the pedal traveled moseso than any booster. In the case of that truck, the Vac Boost unit seemed to have made a big improvement over the hydroboost. Like I said, maybe the hydroboost was defective.

 

[bucket]

The only other thing I did was adjust the load sensing valve located over the rear axle. The rears were locking up too soon which required me to reset the valve, now the front brakes lock first and keep the truck straight in a panic stop.

Wait, what?? You can adjust that valve? Mine has a couple leaves added and the rear brakes don't get enough power.

 

[skysurfer]

Yeah, I guess these were limited production because I couldn't find anything online telling me how to adjust it so it was trial and error until I figured it out.

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You can't see it in this picture, but the longer arm is attached to an arm bolted to the differential. As the suspension sags it rotates the short arm that's bolted to the valve counter-clockwise, increasing brake pressure to the rear.

I removed the nut and short arm, then rotated the stem clockwise (to reduce pressure) a few degrees before reassembly. Took it for a drive and did a few panic stops. Had to do this several times until I got the brakes where I wanted them.

 

[bucket]

Hmm, an adjustable link would make things easier to adjust. I might try that.

 

[HotRodPC]

So this load senseing thing, must be Burb Only? I've noticed that 1500 series Burbs have 2500 brake parts, so obviously Burb has a bigger bakes.

 

[oneluckypops]

So this load senseing thing, must be Burb Only? I've noticed that 1500 series Burbs have 2500 brake parts, so obviously Burb has a bigger bakes.

Nope My K30 has it but its un hooked and bia passed.