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eshover
Active Member

42 Posts

Posted - 08/28/2012 :  09:14:13 AM  Show Profile  Visit eshover's Homepage  Reply with Quote
We have a 2002 Chevy bus that has 145,000 miles on it and am having issues with steering loss at low RPM's. This happens as driver is turning and applies brakes at the same time (turning into a driveway or turnaround). The brake motor activates and also sets off the PRIMARY brake light on the dash. I don't have a flowmeter or gauges to test as they are METRIC fittings.
The pump is listed in the tech manual as an L18. I have not worked on these enough to be very familiar and need some advice.
THANKS,
ED

Wolf0r
Top Member

USA
2179 Posts

Posted - 08/28/2012 :  09:51:10 AM  Show Profile  Reply with Quote
Verify you don't have any kingpins bearings binding up.

“The good thing about science is that it's true whether or not you believe in it.”
Neil deGrasse Tyson
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eshover
Active Member

42 Posts

Posted - 08/28/2012 :  1:23:58 PM  Show Profile  Visit eshover's Homepage  Reply with Quote
I jacked it up and can turn the wheels by hand side to side. There is grease all the way to the top of the king pin also. I greased it all again jacked up and on the ground. Ed
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bwest
Administrator

United States
2348 Posts

Posted - 08/28/2012 :  2:38:27 PM  Show Profile  Reply with Quote
I am assuming this is a B7 chassis. This could very well be a flow issue caused by a faulty brake booster. These pumps rarely fail. This is a no brainer, but make sure you have enough fluid in the resivor and that it is a light viscosity such as automatic trans fluid, someone could have put the heavier type "power steering" fluid in it. (It suppose to take regular automatic trans fluid) You should quiz your driver to make sure he didn't put something in it just to get by or something like that.

Bryan
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eddo
Senior Member

USA
91 Posts

Posted - 08/29/2012 :  09:10:41 AM  Show Profile  Reply with Quote
pardon my ignorance here, but on my older Internationals, this was a sure sign of a loose P/S belt or air in the P/S System.

Is this bus's P/S system belt driven, or gear driven? Beyond that, I would suspect the brake booster too.

Edited by - eddo on 08/29/2012 09:12:52 AM
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bwest
Administrator

United States
2348 Posts

Posted - 08/29/2012 :  09:41:03 AM  Show Profile  Reply with Quote
If this is a B7 chassis with Cat engine it is gear driven. As for air in the system, you might be correct there. I just never thought about it because normally you would have air in the system only if the resivor is low or if there is a leak in the supply line, in which case you would have an empty resivor very soon.

Bryan
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eshover
Active Member

42 Posts

Posted - 09/04/2012 :  05:47:53 AM  Show Profile  Visit eshover's Homepage  Reply with Quote
The PS oil according to the tech manual should be GM.
This has an 8.1L gas engine in it.
Also the power steering pump is driven by a belt w/spring loaded tightener.
ED
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bwest
Administrator

United States
2348 Posts

Posted - 09/04/2012 :  08:57:30 AM  Show Profile  Reply with Quote
OK, I'm out of the loop then. I forgot they still offered the gas in '02. Sorry. Still has the same booster as the Cat has but I'm not sure about the pump.

Bryan
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eshover
Active Member

42 Posts

Posted - 09/21/2012 :  1:17:37 PM  Show Profile  Visit eshover's Homepage  Reply with Quote
Just for information purposes we took this bus to GM dealer and they tested steering pump pressure and it was normal until you really cranked on it then it went way down on pressure. They replaced power steering pump and all works well now. Happy driver now.
ED
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C.HARDY
Advanced Member

354 Posts

Posted - 09/21/2012 :  5:27:09 PM  Show Profile  Click to see C.HARDY's MSN Messenger address  Reply with Quote
I've had the same problem with an International. Push the brake pedal and try to turn and it tightens up. Release the pedal and all is good. I changed the flushed the system and refilled with ATf and changed the P/S filter and havent had any more problems but it may be your booster getting weak.

"Hardybusman"
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Wolf0r
Top Member

USA
2179 Posts

Posted - 09/24/2012 :  09:09:37 AM  Show Profile  Reply with Quote
quote:
Originally posted by eshover

Just for information purposes we took this bus to GM dealer and they tested steering pump pressure and it was normal until you really cranked on it then it went way down on pressure. They replaced power steering pump and all works well now. Happy driver now.
ED



Trusty old power steering analyzer we have one here but don't have all the fittings for the quick connect GM hoses. Smart thinking getting that test done before throwing parts at it.

“The good thing about science is that it's true whether or not you believe in it.”
Neil deGrasse Tyson
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Cal Mc
Advanced Member

252 Posts

Posted - 10/01/2012 :  9:41:50 PM  Show Profile  Visit Cal Mc's Homepage  Reply with Quote
My bet is the gear driven power steering pump. We stock them and have changed lots. If you are putting on a new pump remove the reservoir and clean it. Flush the system with new oil before hooking the return to the reservoir.
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