Cheap and Easy Hydroboost for A-bodies with LQ/LM engines
06-22-2011, 09:19 PM
#1
Cheap and Easy Hydroboost for A-bodies with LQ/LM engines It's been awhile since I have posted a good how-to thread, but life has been hectic and its starting to slow down where I can get back into hot rodding now and make some of your lives easier with my mistakes! So here it goes.
Since running the blower and decent sized cam the last 2 years I have noticed that my brakes, CPP 13"/11" 4 wheel discs, are less than desirable. So with more boost coming this round of mods I thought it would be best to install a hydroboost (HB).
It should be noted I am using a Jeep Grand Cherokee steering gear, which provides a quicker ratio than the stocker, and also has metric fittings, making pressure hose selection much easier.
My engine is an LQ4 that had a HB pump originally, but I traded it on here to a guy doing a conversion on a half ton, I needed to get a HB pump again, so I went out to a salvage yard and found one from an Escalade. I used the trade in value of my non-HB pump and got the HB pump for $25.
From the you pick it yard I removed a HB unit from a 90's Astro van. $30. After some brake cleaner and paint it looks great.
To mount the HB unit to the firewall I used a Talon Hydraulics adapter plate. $112 after shipping.
To adapt the brake rod, install the stock brake rod clevis to the UPPER hole in the brake pedal. Measure from the back of the clevis to the back of the HB. using math simply cut the HB rod down and grind to a point. Cut the stock vacuum booster rod end off and grind to a point as well. Point to point they should measure the length you determined. Weld the rod together and sleeve the rod for strength. Install in car.
I used high pressure hoses for a 85 Olds 88 Royale Diesel. $32 for both.
$199 for a complete setup. Compare that to an aftermarket!
Since running the blower and decent sized cam the last 2 years I have noticed that my brakes, CPP 13"/11" 4 wheel discs, are less than desirable. So with more boost coming this round of mods I thought it would be best to install a hydroboost (HB).
It should be noted I am using a Jeep Grand Cherokee steering gear, which provides a quicker ratio than the stocker, and also has metric fittings, making pressure hose selection much easier.
My engine is an LQ4 that had a HB pump originally, but I traded it on here to a guy doing a conversion on a half ton, I needed to get a HB pump again, so I went out to a salvage yard and found one from an Escalade. I used the trade in value of my non-HB pump and got the HB pump for $25.
From the you pick it yard I removed a HB unit from a 90's Astro van. $30. After some brake cleaner and paint it looks great.
To mount the HB unit to the firewall I used a Talon Hydraulics adapter plate. $112 after shipping.
To adapt the brake rod, install the stock brake rod clevis to the UPPER hole in the brake pedal. Measure from the back of the clevis to the back of the HB. using math simply cut the HB rod down and grind to a point. Cut the stock vacuum booster rod end off and grind to a point as well. Point to point they should measure the length you determined. Weld the rod together and sleeve the rod for strength. Install in car.
I used high pressure hoses for a 85 Olds 88 Royale Diesel. $32 for both.
$199 for a complete setup. Compare that to an aftermarket!
06-02-2013, 11:55 PM
#2
Follow up Hey guys, I want to update everyone on this hydroboost conversion. I did make some changes and have street time on the setup to validate its function.
First, I had to make some changes to the pump input rod. I bought a Talon Hydraulics threaded input rod, stake in type, do not remember the length, sorry. Still attach this to the upper hole in the pedal rod with the stock clevis.
Second, I installed a power return spring kit from Talon on the master cylinder pushrod. The pushrod was not long enough to engage the master cylinder so I made a proper length pushrod from cold rolled rod stock, don't remember the diameter.
The Delta 88 lines did not work because the HB unit is flipped upside down. I cut apart the Delta lines and used some of the hard line portion to get the lines facing forward towards the pump and gear. I then put a 37* flare on the hard lines and used a -06 union to Aeroquip teflon hose and ran to their respective destinations. I also installed a p/s fluid cooler because I had the parts laying around.
I have street time on the setup now and it work absolutely amazing. When I first did an LS swap, I said i will never build another SBC again. After driving with HB, I will never install vacuum assist brakes again!
Here's a pic of the hoses and the master with HB
Uploaded with ImageShack.us
First, I had to make some changes to the pump input rod. I bought a Talon Hydraulics threaded input rod, stake in type, do not remember the length, sorry. Still attach this to the upper hole in the pedal rod with the stock clevis.
Second, I installed a power return spring kit from Talon on the master cylinder pushrod. The pushrod was not long enough to engage the master cylinder so I made a proper length pushrod from cold rolled rod stock, don't remember the diameter.
The Delta 88 lines did not work because the HB unit is flipped upside down. I cut apart the Delta lines and used some of the hard line portion to get the lines facing forward towards the pump and gear. I then put a 37* flare on the hard lines and used a -06 union to Aeroquip teflon hose and ran to their respective destinations. I also installed a p/s fluid cooler because I had the parts laying around.
I have street time on the setup now and it work absolutely amazing. When I first did an LS swap, I said i will never build another SBC again. After driving with HB, I will never install vacuum assist brakes again!
Here's a pic of the hoses and the master with HB
Uploaded with ImageShack.us
Last edited by ryanvv355; 06-03-2013 at 12:04 AM.
06-04-2013, 07:02 PM
#3
Teching In
iTrader: (1)
Join Date: Aug 2012
Location: Sherman, TX
Posts: 41
Likes: 0
Received 0 Likes
on
0 Posts
If you don't mind, I'll add a little of my own experience for doing the hydroboost swap on my '61 Chevy wagon.
I used an Astro van HB unit as well, $25 from my local junk yard.
For the lines I bought new hydroboost lines for an '02-ish Avalanche from the local parts store. One of the lines was $20-22, and the other was $28.
For the hydroboost adapter bracket, my dad is a machinist so I had a bit of a leg up there and we took all the dimensions and made one on the Bridgeport mill my dad has at the shop.
I bought a new '77 Corvette power brake master cylinder from the local parts store for $60 or $70.
I used an Astro van HB unit as well, $25 from my local junk yard.
For the lines I bought new hydroboost lines for an '02-ish Avalanche from the local parts store. One of the lines was $20-22, and the other was $28.
For the hydroboost adapter bracket, my dad is a machinist so I had a bit of a leg up there and we took all the dimensions and made one on the Bridgeport mill my dad has at the shop.
I bought a new '77 Corvette power brake master cylinder from the local parts store for $60 or $70.
06-05-2013, 09:20 AM
#4
So you need to Astro van assembly, a mounting bracket, lines, and if I'm reading correctly a power steering pump from an HD Silverado/Sierra?
Does anyone know if there would be an easy way to adapt said power steering pump to the Corvette accessory bracket? Looks like that could be the deal breaker for me.
Does anyone know if there would be an easy way to adapt said power steering pump to the Corvette accessory bracket? Looks like that could be the deal breaker for me.
06-05-2013, 02:29 PM
#5
I'm thinking about doing this also. My 2007 lq4 came with the right power steering pump. Would there be any issues running HB on my stock disc/drum setup? At some point I want to upgrade the front discs and put discs on the rear but want to keep the cost down for now.
06-05-2013, 02:37 PM
#6
Teching In
iTrader: (1)
Join Date: Aug 2012
Location: Sherman, TX
Posts: 41
Likes: 0
Received 0 Likes
on
0 Posts
I've got the 12" drilled/slotted rotors and Wilwood dual piston calipers on my wagon and drums in the rear, and I don't foresee any problems with running the drums in the rear. I'm actually running the same '07 LQ4 as you, also.
06-05-2013, 04:52 PM
#7
TECH Addict
iTrader: (4)
Join Date: Feb 2002
Location: Enumclaw, WA
Posts: 2,566
Likes: 0
Received 0 Likes
on
0 Posts
So you need to Astro van assembly, a mounting bracket, lines, and if I'm reading correctly a power steering pump from an HD Silverado/Sierra?
Does anyone know if there would be an easy way to adapt said power steering pump to the Corvette accessory bracket? Looks like that could be the deal breaker for me.
Does anyone know if there would be an easy way to adapt said power steering pump to the Corvette accessory bracket? Looks like that could be the deal breaker for me.
Trending Topics
06-05-2013, 08:34 PM
#9
I had HB on my Cummins Dodge and that was the best pedal I ever felt. With vacuum assist and the old Magnacharger, the Cutlass brakes where sketchy at best. With this HB setup my pedal is firm and braking is much more predictable. I get some whining noise during turning but I'm thinking that might be from my whole system being junkyard parts, LOL. HB, P/S pump and steering box all U pick it yard scores.
As far as brake system configuration goes, I am under the impression that it doesn't matter, all you are doing with HB is hydraulically engaging the m/c. If your brakes worked before HB, it should work after. Mine did.
As far as brake system configuration goes, I am under the impression that it doesn't matter, all you are doing with HB is hydraulically engaging the m/c. If your brakes worked before HB, it should work after. Mine did.
11-08-2017, 10:06 AM
#11
Does the 90's Astro Van hydroboost bolt up to the factory A-Body master cylinder? Or do you use the master cylinder off the Astro van as well?
First post was pretty clear, but second post sort of made it go from cheap/easy to difficult/not-so-cheap lol Why was the spring needed? Multiple rods need to be made?
My summary of what only needs to be done (correct me if I'm wrong):
96-02 Astro Van hydroboost unit
Custom bracket to mount hydroboost unit to firewall
Custom rod that goes from pedal to hydroboost
A pressured line from power steering to hydroboost
Pressured line from hydroboost to power steering
return line from hydroboost to reservoir
First post was pretty clear, but second post sort of made it go from cheap/easy to difficult/not-so-cheap lol Why was the spring needed? Multiple rods need to be made?
My summary of what only needs to be done (correct me if I'm wrong):
96-02 Astro Van hydroboost unit
Custom bracket to mount hydroboost unit to firewall
Custom rod that goes from pedal to hydroboost
A pressured line from power steering to hydroboost
Pressured line from hydroboost to power steering
return line from hydroboost to reservoir
