370 Brake stuff

[romakdaddy]

thought I would start another thread about brakes...plus I need some info. I coulda swore I posted about my power brakes a while back but couldn't find it. The gillig chassis uses a strange electric/hydraulic power brake setup and mines acting the fool. question is, whats the name of it and how easy are they to work on? mines not assisting and the motor runs all the time when the drive section power is on.

[bobmiller1]

The system is pretty straight forward ...if the brakes work off a hydro-boost system, should the engine die you would lose the hydro-boost section of the brake system. IE you would have no power assist. Being that you said the motor runs constantly you either have one of two problems. Problem one would be that you already have a very low brake pedal due do some problem in the hydraulic side of the brake system. Problem two is that the brake unit itself is shot. The system works on pressure and when the unit senses low pressure in the brake system when the brake pedal is applied it will turn the electric pump motor on to assist braking. I would first make sure that your hydraulic side is working correctly. Have you done any recent brake work and if so is the brake system been properly bleed out ? If you are not sure I would gravity bleed the brake system first. Remove the cover from the master cylinder and make sure it is full, leave cover off and open all four bleeders. After about five mins. You should see brake fluid coming from all four corners slowly. Make sure to keep master cylinder full during this process by checking every few minutes. See if there are any air bubbles coming out of the bleeders as well. When it is a solid flow of fluid all of the air is gone and it is safe to close the bleeders. Make sure all bleeders are on top of the calipers, I have seen calipers replaced incorrectly with the bleeders on the bottom. Regards, Bob

[romakdaddy]

Originally Posted by bobmiller1

The system is pretty straight forward ...if the brakes work off a hydro-boost system, should the engine die you would lose the hydro-boost section of the brake system. IE you would have no power assist. Being that you said the motor runs constantly you either have one of two problems. Problem one would be that you already have a very low brake pedal due do some problem in the hydraulic side of the brake system. Problem two is that the brake unit itself is shot. The system works on pressure and when the unit senses low pressure in the brake system when the brake pedal is applied it will turn the electric pump motor on to assist braking. I would first make sure that your hydraulic side is working correctly. Have you done any recent brake work and if so is the brake system been properly bleed out ? If you are not sure I would gravity bleed the brake system first. Remove the cover from the master cylinder and make sure it is full, leave cover off and open all four bleeders. After about five mins. You should see brake fluid coming from all four corners slowly. Make sure to keep master cylinder full during this process by checking every few minutes. See if there are any air bubbles coming out of the bleeders as well. When it is a solid flow of fluid all of the air is gone and it is safe to close the bleeders. Make sure all bleeders are on top of the calipers, I have seen calipers replaced incorrectly with the bleeders on the bottom. Regards, Bob

the mh has sat up many years but my dad and step mom remember the brakes practically not working at all when they drove it. it has a firm pedal but too firm like it has no power assist so im not thinking its a brake hydraulic issue but its a problem on the boost/assist side...I remember knowing some years ago what kind it is but couldn't find anything lately(guess ill have to go look at it)...lol

[streamquest]

Bob,

You don't even have your 370 yet, and you are already on the case!! I seriously hope the deal goes through for you.

The first time I test drove my 370, I asked the PO what was up with the brakes?? The thing is a bear to stop, and takes some SERIOUS pedal effort. He claimed that he'd had it checked out, and told me that this is simply the way these things are. Now I wonder if something else may be going on??

You definitely do not tailgate anyone with this thing.

[romakdaddy]

Originally Posted by streamquest

Bob,

You don't even have your 370 yet, and you are already on the case!! I seriously hope the deal goes through for you.

The first time I test drove my 370, I asked the PO what was up with the brakes?? The thing is a bear to stop, and takes some SERIOUS pedal effort. He claimed that he'd had it checked out, and told me that this is simply the way these things are. Now I wonder if something else may be going on??

You definitely do not tailgate anyone with this thing.

maybe theres a better system this beast can run.
BTW wheres the air compressor located?

[streamquest]

Originally Posted by romakdaddy

thought I would start another thread about brakes...plus I need some info. I coulda swore I posted about my power brakes a while back but couldn't find it. The gillig chassis uses a strange electric/hydraulic power brake setup and mines acting the fool. question is, whats the name of it and how easy are they to work on? mines not assisting and the motor runs all the time when the drive section power is on.

r/d,

When you say the "motor" runs constantly, are you referring to the air compressor mounted just behind the front bumper?

That air compressor supports the front air bags (ride height), and the parking brake. The 370 does not have "air brakes" as might be found on a big truck.
I'll post some pics of the system from my Gillig manual.

[romakdaddy]

Originally Posted by streamquest

r/d,

When you say the "motor" runs constantly, are you referring to the air compressor mounted just behind the front bumper?

That air compressor supports the front air bags (ride height), and the parking brake. The 370 does not have "air brakes" as might be found on a big truck.
I'll post some pics of the system from my Gillig manual.

by motor I mean the electric motor on the master cyl. the air compressor question was a random off topic one...lol I was thinking it was behind the bumper but not sure...I've never heard it run the whole time I've owned the 370 so I think it doesn't work(yet another project to tackle)

[bobmiller1]

So, I am curious......how are you making out with your brake concerns.....have your tested the power steering pump pressure ???

[romakdaddy]

I've been concentrating on the interior repairs for now but it's been so hot I have put all things airstream and for the most part outside period on hold...lol

[bobmiller1]

Tell me about hot.....we were at the Lewisburg rally earlier this month and went to NC to inspect the 370. It was 104 degrees....I lasted 4 hours.

[RBonney]

Sorry to jump this thread but I just did a brake job and when I finished new calipers and all rubber lines and master cylinder I noticed my back axle does not appear to be in park. Is there something else I need to bleed or am I all right to fire it up. 1990 345 LE thanks. Hoping to hit the road tomorrow for a week road trip.

[bobmiller1]

After our trip to Cooperstown it is obvious to me that I need new rotors.....has any one replaced their's without going through Gillig and if so do you remember where you got them and the part numbers ? Regards, Bob

[streamquest]

Bob,

Since changing the pads, I thought you were reasonably happy with the brakes.
Why new rotors?

Charly

[bobmiller1]

Brakes are good, pedal travel is good, long down hill descent tells me that when they get hot they must be warped, steering wheel shakes like crazy while brake pedal is depressed. Thought about resurfacing them, but as long as they're off, if I can find new ones, I'de rather go that way.