| Power Steering Pump [message #296734] |
Sat, 05 March 2016 08:56  |
Bruce Hart
Messages: 1501
Registered: October 2011
Location: La Grange, Wyoming
Karma: 5
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Senior Member |
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Using the GMCMI parts book I ordered the power steering pump NAPA part # 38-1236
Only five existed in the NAPA network and all five were in Tennessee, I live in Colorado.
When I received the pump the pulley shaft had a key slot and threaded end for a nut.
My original pulley has a press fit no key slot and no threaded end. What style is correct for the GMC
Another option that is given in the GMCMI parts list is #38-1257, but I was told it was not available
through NAPA.
Attention Kim
Bruce Hart
1976 Palm Beach
1977 28' Kingsley
La Grange, Wyoming
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| Re: Power Steering Pump [message #296740 is a reply to message #296734] |
Sat, 05 March 2016 11:06  |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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Senior Member |
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My pump had the slotted shaft and nut. Just get the correct diameter pulley ,key,and nut to fit the pump from Napa or a wrecking yard.
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: [GMCnet] Power Steering Pump [message #296744 is a reply to message #296734] |
Sat, 05 March 2016 12:53 |
Kosier
Messages: 834
Registered: February 2008
Karma: 1
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Bruce,
IIRC, the pump with the tapered shaft and nut stopped at 73 and all the
later stuff is press on.
All the later pumps are basically the same. The difference is in the
reservoir and pulley.
The pulley on the GMC is sort of unique, so don't let yours get away. MOST
of the reservoirs
differ in the location and angle of the return line. I've interchanged
reservoirs around,
sometimes beneficial, sometimes disaster. YMMV
Gary Kosier
77PB w/500Cad
Newark, Ohio
--------------------------------------------------
From: "Bruce Hart"
Sent: Saturday, March 05, 2016 9:56 AM
To:
Subject: [GMCnet] Power Steering Pump
> Using the GMCMI parts book I ordered the power steering pump NAPA part #
> 38-1236
> Only five existed in the NAPA network and all five were in Tennessee, I
> live in Colorado.
> When I received the pump the pulley shaft had a key slot and threaded end
> for a nut.
> My original pulley has a press fit no key slot and no threaded end. What
> style is correct for the GMC
> Another option that is given in the GMCMI parts list is #38-1257, but I
> was told it was not available
> through NAPA.
>
>
> Attention Kim
> --
> Bruce Hart
> 1976 Palm Beach
> Milliken, Co
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
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| Re: Power Steering Pump [message #296849 is a reply to message #296764] |
Sun, 06 March 2016 20:55 |
Keith V
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
Karma: 0
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Senior Member |
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any parts hose can get you the pump only, then you can reuse your can and valve which is the important part.
And yes get new...
Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
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| Re: Power Steering Pump [message #296869 is a reply to message #296734] |
Mon, 07 March 2016 10:02 |
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John Heslinga
Messages: 632
Registered: February 2011
Location: Edmonton, Alberta, Canada
Karma: 4
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Senior Member |
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Bruce.
I have some thoughts for you if I may.
While the basic power steering pump that GM uses is exactly the same there are a lot of differences between applications and the details of each pump. As you can see there are a number of different power steering pumps details that were changed over the years of our coachs. The earlier years had pulleys that used a taper shaft and a nut as their mounting strategy. The later years used a press on pulley that uses a special tool to remove and install. There are also some other differences as well. In the earlier years the pressure line was a 3/8 inch double flare fitting and the later years it used an o-ring style of pressure line fitting. That double flare fitting can sometimes be a real bear to remove and you should be prepared to repair the damage on its removal. I am Not sure when the changes were made or if they we done concurrently but you could get a good clue by checking out the factory TZE parts book.
The front pulley on many of the coaches has three holes which allows you access to a couple of the bolts making it easier to work with that pump. Other pulleys for diffent applications without holes may cause you some problems when you install the pump. Also be very careful with that pulley because it bends very easily. However it also straighten StreetEasy so check it out for straightness before installing the entire pump.
The "ham can" type of reservoir used for that pump is unique for different applications of that pump. It is very unlikely that you will able to get a power steering pump that has the ham can installed already. When you have that reservoir removed ensure that you flatten the metal at the mounting bolts and clean all surfaces that the o-rings come in contact with to ensure good seal of that reservoir.
Another issue is the pressure a flow valving of the power steering pump. Our coaches actually have a design pressure and flow that's greater than most vehicles. The pump that you get from the parts store will likely have a pressure setting that will be lower than your original coach setting. While these settings can be adjusted it is a hit and miss type of thing without working with the pump on a test bench. That would mean taking the pump in and out of the coach and measuring the pressures a few times. Not something you really want to do. The answer to that has been to exchange the old pressure and flow parts from the old pump and installing them in the new rebuilt pump. However sometimes that is what was the problem with the old pump. You simply might change the problem from the old pump to the new pump. Again another crap shoot. A pump that was breaking down could be putting contaminants and plugging a screen on the pressure valve that is very difficult to take apart and clean and if you do not exchange those parts you inherent the lower pressure settings of the new pump. While many people except that pressure and don't really feel the difference there is a minor difference in feel. Also you should take apart and disassemble the filter in the windshield washer motor and clean that screen out thoroughly. Unfortunately solvent and air will not do it effectively. The material that plugs that screen is Metal from the pump vanes and housing. The magnet in the reservoir helps to contain it but it comes after the WW filter in the oil flow
It really is important that you completely flush the entire system, install an inline power steering filter and put in fresh power steering fluid. A 3/8 inch Cardone in line filter is one example. Search for it on Amazon - the last 2 numbers are 38 (about 20 bux)
John and Cathie Heslinga
1974 Canyonlands 260
455, Manny tranny and 1 ton, 3:70 LS,
Red Seal Journeyman, DTE, BEd. MEd.
Edmonton, Alberta
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