Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×

Thread Tools Display Modes
Old 06-01-2011, 06:59 AM   #1
New Member
Join Date: Aug 2009
Posts: 8
Year: 1985
Coachwork: Blue Bird
Chassis: International
Engine: 9L family International
Rated Cap: 62
86 International Hydraulic Brakes

I need a little help explaining the system/finding parts for my 86 International. The system was of the electric assist type, where the electric motor would provide boost when the bus was off in case the bus started rolling with the engine off.

My buddy blew out a brake line driving the bus around his property. Upon replacing the brake line and bleeding the caliper, the brakes were really stiff, which I first thought was good (thinking of my dad always liking a hard brake pedal) but then realized I was getting no brake action. I am assuming this has to do with the hydraulic engine driven pump, but the electric motor does not even come on now with the bus off.

Is the hydraulic pump independent of the power steering? I see a small fluid drip running down the steering column into the steering box (I think that is what it is).

Just trying to get a little background before I start ripping into things...

Thanks guys!

hmacris is offline   Reply With Quote
Old 07-25-2011, 01:34 AM   #2
Jive Turkey's Avatar
Join Date: Jun 2009
Location: Alberta
Posts: 47
Re: 86 International Hydraulic Brakes

Did ya get'r fixed or figured out yet?
Jive Turkey is offline   Reply With Quote
Old 07-26-2011, 12:13 PM   #3
Join Date: Feb 2010
Posts: 11
Year: 1988
Coachwork: Blue Bird
Chassis: International
Engine: DT466C
Rated Cap: 60
Re: 86 International Hydraulic Brakes

The system is called Hydro Max, if you're looking for info. Uses a 2" bore master cylinder. Similar to the Hydroboost on Chevy trucks, just much beefier. From my understanding the backup motor will run until pressure is built up. If there is a leak, it will run continually. For how long I don't know. Mine wasn't building pressure, and going through a lot of brake (break for the illiterate) fluid. Ah, yes, someone left the left rear brake nipple open. Once I snugged that, the boost motor stopped running. Parts are readily available, either the master cylinder or booster. Not cheap though.
martian is offline   Reply With Quote
Old 07-30-2022, 05:44 PM   #4
New Member
Join Date: Jul 2022
Posts: 1
Year: 1998
Coachwork: Crown
Chassis: IH3800
Engine: T444E
Rated Cap: N/A
I am getting a drip of PS fluid out of the motor is there a seal where it bolts to booster or does the entire unit need to be replaced
DSSR is offline   Reply With Quote
Old 07-31-2022, 10:40 AM   #5
Bus Nut
Join Date: Feb 2019
Location: Communist State of New Jersey
Posts: 964
Year: 2004
Coachwork: IC
Chassis: CE200
Engine: T444e
Rated Cap: 27,500
Originally Posted by DSSR View Post
I am getting a drip of PS fluid out of the motor is there a seal where it bolts to booster or does the entire unit need to be replaced
First, welcome to the forum.

I suggest you start a new thread instead of adding a post to an 11 year old thread.

What you're asking isn't clear. A drip, as in one, or is it dripping continuously? Motor as in engine or are you talking about the power steering pump (which is probably also the power brake booster)? What unit, the PS/PB booster pump? Please clarify so someone can provide accurate, concise help for you.
Oldyeller is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
1999 BlueBird International - Rear Brakes NilesSkoolie International | Navistar Drivetrain 8 03-04-2013 12:38 PM
1991 BlueBird TC2000 Hydraulic/Hydraulic Brakes Sticking C00LR Mechanical and Drivetrains 0 10-15-2009 10:11 AM
International brakes TOM Everything Else | General Skoolie Discussions 1 09-21-2008 08:44 AM
hydraulic to air brakes adamanderr Conversion General Discussions 2 01-03-2008 10:35 PM
Problem with brakes/Starting (hydraulic?) Les Lampman Conversion General Discussions 5 12-16-2006 09:56 PM

» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 02:47 AM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.