Hydro boost units, who's got 'em?
10-08-2007, 04:34 PM
#16
Registered User
I have completed my hydroboost conversion, all I can say is WOW, I also upgraded to the chevy rear wheel cylinders as well. I just put on 35x12.5 tires all at the same time and the truck still stops better. I am at $425 for the parts.
A few people at SOP wanted the applications I used and some basic instructions.
First I got a junk yard hydroboost unit for a 1990 1 ton chevy c/k30. You will need a junkyard unit for the core, the internal spring mechanism, and the mounting bracket. 60$
Then from napa I ordered a new hydroboost unit for the same application, I also ordered all the hoses for the same application. 250$
Two holes in the mounting bracket are the same as the Dodge vaccum boosters, two new holes will need to be drilled in the firewall. Weld (4) 3/8" x about 2" long bolts to the chevy square bracket (this is optional but makes slipping the bushings on later much easier. The hydro booster requires a large square socket which we made from some tubing. There is a small bracket that supports the lines which hangs from the master cylinder bolts, the oval holes will need to be widened slightly this can be done with a die grinder or round file.
I choose NOT to modify the push rod, it need to be shortened about
1 5/16", so I made aluminum spacers to move the booster farther into the engine compartmet. Why? Well this makes spare parts much easier to get in the future. I had no clearance problems with the cooler tubes. I also needed a small bushing to adapt the GM rod end to the dodge pin, .503" id .568" od. I supposed one could have drilled out the brake side of things and put in a larger pin. Remove the rubber boot and foam spacer from the junkyard booster and slide it over the push rod before sliding the it through the firewall. Some thick HDPE foam cut to fit would have been great here.
The dodge master cylinder will not work with the chevy hydrobooster, the end configuration is slightly different. So with some carefull research on Autozone online I ended up getting a 1991 chevy k30 (1 ton) master cylinder with heavy duty brake option "JB8 hydroboost" I got this part from Autozone new with no core and resivour. This has the same size fittings as stock dodge with a 1.250" bore. I am not sure if a hydroboost unit from this application would fit our trucks. $90
The final piece of the puzzle was the 2000 dodge powersteering pump I aquired from eBay. This unit had an addtional return, has larger internal bearings and will bolt to our vaccum pump, use locktite on the 10mm studs and nuts! $25
You will also need some plastic tube adapters to change the vaccum line connection that feeds the dash vents and cruise, this was minor just some tube adapters I had lying around.
As many have said this was one of the best mods for my truck. and it nearly looks factory done with all of the shelf parts, in a pinch the truck could be returned to vaccum brakes as well.
A few people at SOP wanted the applications I used and some basic instructions.
First I got a junk yard hydroboost unit for a 1990 1 ton chevy c/k30. You will need a junkyard unit for the core, the internal spring mechanism, and the mounting bracket. 60$
Then from napa I ordered a new hydroboost unit for the same application, I also ordered all the hoses for the same application. 250$
Two holes in the mounting bracket are the same as the Dodge vaccum boosters, two new holes will need to be drilled in the firewall. Weld (4) 3/8" x about 2" long bolts to the chevy square bracket (this is optional but makes slipping the bushings on later much easier. The hydro booster requires a large square socket which we made from some tubing. There is a small bracket that supports the lines which hangs from the master cylinder bolts, the oval holes will need to be widened slightly this can be done with a die grinder or round file.
I choose NOT to modify the push rod, it need to be shortened about
1 5/16", so I made aluminum spacers to move the booster farther into the engine compartmet. Why? Well this makes spare parts much easier to get in the future. I had no clearance problems with the cooler tubes. I also needed a small bushing to adapt the GM rod end to the dodge pin, .503" id .568" od. I supposed one could have drilled out the brake side of things and put in a larger pin. Remove the rubber boot and foam spacer from the junkyard booster and slide it over the push rod before sliding the it through the firewall. Some thick HDPE foam cut to fit would have been great here.
The dodge master cylinder will not work with the chevy hydrobooster, the end configuration is slightly different. So with some carefull research on Autozone online I ended up getting a 1991 chevy k30 (1 ton) master cylinder with heavy duty brake option "JB8 hydroboost" I got this part from Autozone new with no core and resivour. This has the same size fittings as stock dodge with a 1.250" bore. I am not sure if a hydroboost unit from this application would fit our trucks. $90
The final piece of the puzzle was the 2000 dodge powersteering pump I aquired from eBay. This unit had an addtional return, has larger internal bearings and will bolt to our vaccum pump, use locktite on the 10mm studs and nuts! $25
You will also need some plastic tube adapters to change the vaccum line connection that feeds the dash vents and cruise, this was minor just some tube adapters I had lying around.
As many have said this was one of the best mods for my truck. and it nearly looks factory done with all of the shelf parts, in a pinch the truck could be returned to vaccum brakes as well.
10-09-2007, 02:22 PM
#21
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I may just have to go rob the boost unit off that 80 chevy out in the pasture. Looks exactly like that one.
Thanks for the info and pics.
This would be a good one for the sticky!
Andy
Thanks for the info and pics.
This would be a good one for the sticky!
Andy
01-18-2008, 10:03 AM
#22
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Looks like it's time for me to do this one. It sounds like this is probably the best brake solution available for my truck. I just made a list of the parts that were used. Thank you for the excellent pictures and writeup.
One question though. How does the length compart to the stock setup. i have a p-pump in there that is quite a bit longer than the VE.
RonA
One question though. How does the length compart to the stock setup. i have a p-pump in there that is quite a bit longer than the VE.
RonA
03-14-2008, 09:22 PM
#24
Registered User
Looks complicated, I'm confused what makes this unit better then our's? I am having some brake troubles, they get extremely stiff when I put on the brake and becomes tricky to stop. I'm sure that there is a leak of some sort, is it work fixing my booster or upgrade to this?
03-20-2008, 05:05 AM
#26
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The advantage of hydraulically boosted brakes is that you can get more pressure to the brake cylinders easier.
We have a '92 GMC Rally Van and an '87 GMC 7000 Straight truck (14 ton) both of which have hydraulically boosted brake systems. On both of those vehicles you never have to push on the pedal hard to get good braking. And when they are bled out well it does not take much pedal travel to get hard braking.
Every time I drive those GMC's I think "I wish I had these brakes in my W250."
JP.
We have a '92 GMC Rally Van and an '87 GMC 7000 Straight truck (14 ton) both of which have hydraulically boosted brake systems. On both of those vehicles you never have to push on the pedal hard to get good braking. And when they are bled out well it does not take much pedal travel to get hard braking.
Every time I drive those GMC's I think "I wish I had these brakes in my W250."
JP.
03-20-2008, 05:51 AM
#27
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Thread Starter
They work better because they use hydraulic pressure as opposed to vacuum. I went from standing on the brake pedal to stop to just setting my foot on it.
03-20-2008, 09:02 AM
#28
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Its not, there's 3 hydraulic hoses, disconnect the one from the power steering pump to the steering box. Hook the 1 hose up directly from the hydro boost unit to the pump, the other hose goes to the steering box and the the last one is returned to the reservoir.
They work better because they use hydraulic pressure as opposed to vacuum. I went from standing on the brake pedal to stop to just setting my foot on it.
They work better because they use hydraulic pressure as opposed to vacuum. I went from standing on the brake pedal to stop to just setting my foot on it.
Ron
03-20-2008, 04:07 PM
#29
Registered User
Its not, there's 3 hydraulic hoses, disconnect the one from the power steering pump to the steering box. Hook the 1 hose up directly from the hydro boost unit to the pump, the other hose goes to the steering box and the the last one is returned to the reservoir.
They work better because they use hydraulic pressure as opposed to vacuum. I went from standing on the brake pedal to stop to just setting my foot on it.
They work better because they use hydraulic pressure as opposed to vacuum. I went from standing on the brake pedal to stop to just setting my foot on it.
I guess the pictures make it look more confusing then it really is. So if I understand this correctly I need to get one from a junk yard so I can turn it in as a core? Also what year GM trucks do I need to look out for? Would it be a good I dea to just change out all of the hoses?
Thanks, and like you I am tired of standing on the brakes
