I think I'm giving up on the hydroboost brake system...

Macro1

Well-known member
May 14, 2010
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Long story short, I bought Lanes old Hydroboost brake conversion parts, installed and havent ever worked right.

Bought a new master cylinder...
Installed SS brake lines...
Using Defender Rotors (DBA I believe) with Bill at GBR's caliper spacing kit...

I've been fighting the brakes for over a year now and I think I'll throw in the towel. Im constantly loosing fluid from the forward reserve, the dang things have "gone out" on me 3 times (Once up a local canyon), and now they are out again.

I even think the Hydroboost itself is leaking. Not to mention the dang thing groans and whines like a POS.

If anyone has had REAL (seriously, put your ego aside for a moment) positive, lasting results with this type of brakes on the rover I would love to know so I could correct 'em. Otherwise I'm about ready to order a new Land Rover MS and brake booster.

:victory:
 

KyleT

Well-known member
Mar 28, 2007
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Fort Worth, TEXAS
my bro went through something that sounds similiar on his f150 he put some hydroboost on. IIRC it was a crappy remaned master cylinder.

to fix the moaning, IIRC he had to clean out the pressure bypass? ill ask him when I can. He got it working and it seems to stop his truck pretty dang hard. he has 1ton running gear on it.
 

Macro1

Well-known member
May 14, 2010
116
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KyleT said:
my bro went through something that sounds similiar on his f150 he put some hydroboost on. IIRC it was a crappy remaned master cylinder.

to fix the moaning, IIRC he had to clean out the pressure bypass? ill ask him when I can. He got it working and it seems to stop his truck pretty dang hard. he has 1ton running gear on it.
Interesting. Let me know if you find out anything.

Its not just the groaning, its mainly the dang things have been pretty unreliable even with the new master cylinder and having bench bled the thing a few times plus bleeding the whole system because the brakes will just "go out" or stop working completely. No leaks other than a small amount of PS fluid from the back of the booster itself.
 
Any pedal effort related problems? Aside from the failures? What condition is the accumulator in?

If the accumulator is shot or weak (low gas pressure) then several things happen. The first is that the accumulator overfills; more fluid with no gas pressure to push it back. That increases the duty cycle on the pump to operate the brakes because there is not enough reserve in the accumulator.

It also will cause pedal effort to increase quickly but with little braking power. This would be most noticeable at low engine RPM where pump output can't mask the problem.

It can also result in groaning or hammering noises in the hydraulic circuits.
 

Mongo

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Apr 19, 2004
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My first junkyard hydro-boost did the same thing, I replaced it with a vanco and have had zero issues since. I also changed out my power steering pump with a tg pump that runs at 4.5gpm at 1650 psi...
 

KyleT

Well-known member
Mar 28, 2007
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Fort Worth, TEXAS
Mongo said:
My first junkyard hydro-boost did the same thing, I replaced it with a vanco and have had zero issues since. I also changed out my power steering pump with a tg pump that runs at 4.5gpm at 1650 psi...
post up how you mounted that please?
 

Macro1

Well-known member
May 14, 2010
116
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Injuhneer said:
Any pedal effort related problems? Aside from the failures? What condition is the accumulator in?

If the accumulator is shot or weak (low gas pressure) then several things happen. The first is that the accumulator overfills; more fluid with no gas pressure to push it back. That increases the duty cycle on the pump to operate the brakes because there is not enough reserve in the accumulator.

It also will cause pedal effort to increase quickly but with little braking power. This would be most noticeable at low engine RPM where pump output can't mask the problem.

It can also result in groaning or hammering noises in the hydraulic circuits.

Pedal braking isn't exactly what I would have expected. Its definitely "stiffer" than stock but with less braking power. I also drive a 2004 GMC 2500 Duramax with hydroboost that feels more like a vacuum system. The hydroboost on the rover is definitely "stiffer" and doesn't brake anywhere near as well. In fact the wife has been wanting me to put the old vacuum system back in ever since I installed it.

What is the best way to test the accumulator?
 

Macro1

Well-known member
May 14, 2010
116
0
Mongo said:
My first junkyard hydro-boost did the same thing, I replaced it with a vanco and have had zero issues since. I also changed out my power steering pump with a tg pump that runs at 4.5gpm at 1650 psi...

$650+ for the brakes system? Looks nice but ouch.
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Is it too much to want my truck to brake like 99% of the vehicles out there?
 
Last edited:

Mongo

Well-known member
Apr 19, 2004
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Kyle,
I took a stock mounting plate and customized it...there's a guy who actually made a kit, think I saw it over on
lro

Call me crazy, but dropping a grand to make sure my truck can stop in a emergency and get rid of a problematic abs system wasn't a problem for me...
 

post

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May 6, 2006
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Mtn Home, Idaho
www.cardomain.com
robertf said:
You won't be the first to remove a hydroboost from a disco.
Thats true, I guess hydroboost will work good if you put the money into it and buy a quality hydroboost system but like most budget mods, they usually suck. I got rid of my HB and just went with D90 brakes.
 
Macro1 said:
What is the best way to test the accumulator?
It depends on the type of unit. The internal units are integrated into the piston/spool inside. The external type are screwed into the unit base. External accumulators can be removed and pressure tested but that takes a test frame. The internal type can as well but requires disassembly.

The foot test:
Shut off the engine.
Pump the pedal 3-4 times then hold it down for 30-40 seconds. That will discharge the accumulator.

Keep holding the pedal and start the engine. The pedal should fall, then rise against your foot. If this is the case then the boost unit is working correctly.

If the accumulator is weak the pedal effort will increase substantially before the third try. If you have 4+ pumps on the pedal before the effort rises the accumulator is OK.

If the unit operates correctly on the foot test and the accumulator seems good then it becomes likely a supply problem (pump pressure or volume).
 
post said:
Thats true, I guess hydroboost will work good if you put the money into it and buy a quality hydroboost system but like most budget mods, they usually suck. I got rid of my HB and just went with D90 brakes.
Just a proper install will work wonders. And by that I mean proper components and fitting.

There are plenty to choose from. Ford Mustangs (Cobra and V8) since 1996, most GM 2500/3500 trucks, Dodge RAM (Cummins turbo), Ford Super Duty diesels, and all H2 Hummers. Then there are all the commercial truck variants as well.

Plenty of options.
 

Frank Matiella

New member
Mar 8, 2013
1
0
Oakton, VA
Long story short, I bought Lanes old Hydroboost brake conversion parts, installed and havent ever worked right.

Bought a new master cylinder...
Installed SS brake lines...
Using Defender Rotors (DBA I believe) with Bill at GBR's caliper spacing kit...

I've been fighting the brakes for over a year now and I think I'll throw in the towel. Im constantly loosing fluid from the forward reserve, the dang things have "gone out" on me 3 times (Once up a local canyon), and now they are out again.

I even think the Hydroboost itself is leaking. Not to mention the dang thing groans and whines like a POS.

If anyone has had REAL (seriously, put your ego aside for a moment) positive, lasting results with this type of brakes on the rover I would love to know so I could correct 'em. Otherwise I'm about ready to order a new Land Rover MS and brake booster.

:victory:
I had issues with my 74 Bronco. I put a 4BT cummins in it which has no vacumn. It also never stopped very well. I went through 3 units and master cyliunders. I had the guys at Brake Max in Marana AZ (Tucson) work on the Bronco 3 times at $300. A pop. Nothing! These guys are not the sharpest knives in the drawer! I noticed that the unit and componenets were running way hotter than the engine. I forgot to reinstall the fluid cooler. Installed it and my problems were over and have excellent brakes. Do not buy junkyard stuff., Buy a new one with corresponding master cylinder. And for goodness sake, install a fluid cooler in front of the radiator.
My 97 Disco in next.

Best regards