For those with a Hydroboost Set up

[1970Moparmann]

Had a good day until I lost my brakes.   I have a Hydroboost and lost the system today.   The Power Steering fluid was about 1/4 bottle low, but I would be shocked that that is the issue.   Anyone have any ideas on a good progression to troubleshooting?

- Checked for power steering fluid leaks - none
- Checked the hoses - all look good.

I drove about 100 miles today and all was good.  While I was driving, I noticed I was losing some pedal but still had brakes.  Luckily I was pulling into a friends house at the time.  Car sat, started it up, basically nothing.

Thanks for the help guys!

[bill440rt]

Whoa, that's not a reassuring feeling. 

- Have you since topped off the P/S pump, and if so do you have power brakes again?
- Have you checked your M/C, lines, and fittings to see if there is a leak in your brake system? Is your M/C full?
- Have you checked your prop/distribution valves for any leakage?

[1970Moparmann]

Whoa, that's not a reassuring feeling. 

- Have you since topped off the P/S pump, and if so do you have power brakes again?
- Have you checked your M/C, lines, and fittings to see if there is a leak in your brake system? Is your M/C full?
- Have you checked your prop/distribution valves for any leakage?

No crap!  Luckily I wasn't far from home. I did the above visual checks and since all looked good, I limped it home.

All of the above is negative.   

[MSRacing89]

Had a good day until I lost my brakes.   I have a Hydroboost and lost the system today.   The Power Steering fluid was about 1/4 bottle low, but I would be shocked that that is the issue.   Anyone have any ideas on a good progression to troubleshooting?

- Checked for power steering fluid leaks - none
- Checked the hoses - all look good.

I drove about 100 miles today and all was good.  While I was driving, I noticed I was losing some pedal but still had brakes.  Luckily I was pulling into a friends house at the time.  Car sat, started it up, basically nothing.

Thanks for the help guys!

I am a bit confused, are you saying it came back and started working after it sat?

Did the pedal assist feel like it went away, or did it just go to the floor?  If you lost the Hydraboost then the car would feel like a manual brake car x10.  You should be able to still stop the car, not easily, but you should still have pedal.

If the pedal is going to the floor then you have a brake problem.  Lost a seal in a caliper or brake fitting failure.  I popped a rear seal on caliper with this system.  Have to remember this hydraboost moves a lot a pressure.

[1970Moparmann]

Had a good day until I lost my brakes.   I have a Hydroboost and lost the system today.   The Power Steering fluid was about 1/4 bottle low, but I would be shocked that that is the issue.   Anyone have any ideas on a good progression to troubleshooting?

- Checked for power steering fluid leaks - none
- Checked the hoses - all look good.

I drove about 100 miles today and all was good.  While I was driving, I noticed I was losing some pedal but still had brakes.  Luckily I was pulling into a friends house at the time.  Car sat, started it up, basically nothing.

Thanks for the help guys!

I am a bit confused, are you saying it came back and started working after it sat?

Did the pedal assist feel like it went away, or did it just go to the floor?  If you lost the Hydraboost then the car would feel like a manual brake car x10.  You should be able to still stop the car, not easily, but you should still have pedal.

If the pedal is going to the floor then you have a brake problem.  Lost a seal in a caliper or brake fitting failure.  I popped a rear seal on caliper with this system.  Have to remember this hydraboost moves a lot a pressure.

Pedal is to the ground.  I was going to start in the back disks and work forward.  Thanks for the response, just wanted to get another opinion.   

[MSRacing89]

If nothing turns up, go to a new a M/C.  Again, a lot of pressure behind that hydraboost, I suggest a good replacement like Wilwood or some other higher dollar component.

You can crimp the back brakes off at the soft line to the axle housing and see if your pedal comes back.  That may be a quick way to check the rears.

[1970Moparmann]

Great idea.  I have a Willwood MC now, so hopefully that isn't the issue.

[xpbprox]

When there is a problem with the MC or air in the brake fluid system sometimes I'll see a hydoboost unit just keep the pedal down like what's happening to you. Have to tried to pull the pedal back up

[1970Moparmann]

When there is a problem with the MC or air in the brake fluid system sometimes I'll see a hydoboost unit just keep the pedal down like what's happening to you. Have to tried to pull the pedal back up

Haven't had a chance to look yet.  This Sunday will be mechanic day.   I'll let you know what I come back with.  The brake system has been 100% for 5,000 miles.....

[ws23rt]

Being low on fluid in the PS pump could have introduced air into the system and the accumulator (the back up for braking if loss of PS pressure) used up its duty. I am forever an optimist.
As to how to bleed the system I am at a loss

[tan top]

going for a hydroboost set up some time  in the future , thought I would ad this     remember reading somewhere , to use the proper  power steering  fluid , & not ATF , as the trans fluid can froth up

[bill440rt]

Bleeding the system just entails turning the steering wheel lock to lock.
Brake system bleeds with the usual procedure as well.

[xpbprox]

Running ATF is fine. Ford recommends running ATF in the P/S system. I believe the system running better on tranny fluid. If you wanted to run a syn fluid, I'd go with Mercon SP

[1970Moparmann]

Well, I looked at each caliper, all the hoses, re-bled the whole systems and still nothing.   When I worked in the power steering pump again, it did give a good burp of fluid, but still no brakes.  There was definitely air in the system, but after all of this today still no brakes.  I'll call Hydratech tomorrow and see what they suggest.

[MSRacing89]

Well, I looked at each caliper, all the hoses, re-bled the whole systems and still nothing.  When I worked in the power steering pump again, it did give a good burp of fluid, but still no brakes.  There was definitely air in the system, but after all of this today still no brakes.  I'll call Hydratech tomorrow and see what they suggest.

I am going to guess you have an internal M/C failure.

[1970Moparmann]

I am going to guess you have an internal M/C failure.

You are correct!  Just changed it out today with the one from Wilwood.  Works great....

[bill440rt]

Good to hear!
You had a Wilwood M/C before? Do you know why it failed? How old was it?

[1970Moparmann]

Good to hear!
You had a Wilwood M/C before? Do you know why it failed? How old was it?

Bill, it was from Asbestos, not Wilwood.  They look almost identical

[bill440rt]

OK, thanks.
You had shivers going up my spine.