1989 Elandan Relacement Fuel Pressure Regulator & Installation

defkaf · February 01, 2011, 03:41 PM

I could smell gasoline off an on after stopping throughout most of last year. Mostly outside of the coach, but sometimes strong in the rear bedroom ('89 Elandan).

While winterizing at the end of the year, I finally found fuel leaking from what I have learned is the fuel pressure regulator mounted in the passenger side frame rail adjacent to the gas tank.

Apparently the GM part # 1559833 costs around $200, but people have written that Holley #12-803 is a suitable replacement for around $30 - $40.

I just want to confirm that the proper Holley number is 12-803 and not the bypass model 12-803BP before I order one. We're about to be nailed by, what according the media hype, is surely going to kill us all under the biggest blizzard of all time. Assuming I survive, I want to order the regulator and have it ready to install as soon as I can in the spring.

Also, does anyone have any idea how hard it is to remove and replace this? I assume that since I can see it, or part of it, that I can replace it without too much trouble.

Thanks in advance,

Don

tcsummerville · May 10, 2011, 06:19 PM

My understanding is the 12-803 and NOT the bypass model. I'll be doing the same repair on my 88 SuperChief. The 12-803 looks very similar to the OEM version. It will be a PITA but better than leaking gas while driving.

defkaf · May 19, 2011, 11:43 AM

Further update if anyone can use the info.
I ordered the 12-803 and it is, indeed, the proper part. I turned the motorhome sideways in my driveway so the the back end hung over a steep incline, by doing so I was able to work under the fuel tank area somewhat comfortably. I was able to remove the single mounting bolt on the regulator bracket and pull it part way out of the frame rail. The fuel line going forward to the engine was a rubber line for about 3 feet until it was mated to a steel fuel line going the rest of the way forward. This was the line that was preventing me from being able to pull the regulator fully out of the frame rail. Best option seemed to be to cut this line, since it would be easy to replace, and pull then regulator out far enough to remove the input line from the back of the regulator.
At this point I looked long and hard at what the chances were of removing the input line, and being able to replace it, without cracking or splitting it. Breaking it would leave a 15,000 pound immoveable (without a tow truck) object sideways in my driveway. I was probably about 70 - 80% sure I could do it, but that may have been optimistic. I decided to put it back together and look into other options.
The garage where I try to send work when I can (cousin's husband) also didn't want to take the chance of disabling it without the ability to move/finish it properly if there was a problem. The nearest RV place told me they don't do chassis work and referred me to an International truck service place nearby. They were great to work with. Since they are used to dealing with over-the-road trucks who don't like down time, they were right on it. They also had plenty of large bays and jacks that made it a breeze for them to lower the fuel tank without draining it. It had been filled before parking it for the winter last fall. A 75 gallon tank was nothing for them to handle. They also had no issue with installing the part I had purchased elsewhere. A bit expensive at $110/hour, but it seemed like the most viable option.
Good luck if you tackle it yourself, certainly do-able if you have just a tad more access than I did. Or maybe start with an almost empty tank so that if you did have to drop or shift the tank yourself it would be easier to do.

Don

Oz · May 21, 2011, 12:51 PM

Thank you for that update!

tcsummerville · May 22, 2011, 08:16 PM

I just completed that repair on mine today. I cut the output line, as I couldn't get to the hose clamp connections down stream. I decided to replace the 1/2" ID line forward anyway. Once cut there is enough slack on the 3/8" line from the fuel pump to get wrenches on the fittings without stressing the hose. The Holley part is identical in appearance to the OEM part except for the chrome plating. In addition the Holley part will fit on the original mounting plate without modification. Hope this helps anyone else facing this repair.

enigma960080 · May 23, 2011, 10:00 PM

This may sound like a stupid question, but are your coaches fuel injected? I have an 89 SuperChief with the 454, while I have not been around the top of the tank, I was not aware of a Pressure Regulator with a carburetor. i??

DaveVA78Chieftain · May 24, 2011, 03:16 PM

GM started installing a high pressure pump in the tank with an external regulator (right rear frame rail) in late 1985. They did not start converting to FI until 1990. All this is shown in Appendix 7-7 of the Chevy/GM P-30 Service and Maintenance Manual that is free for download from the Members Free Manual section.

Page 7-44 for carburated (regulator required)
Page 7-45 for FI (no regulator required)

These setups were in response to some of the vaporlock problems GM was encountering.

Dave

boogie_man · June 01, 2015, 01:28 PM

They sell rebuild kits for these too, cheaper alternative to an entire unit. Did mine a year ago, still holding. Congrats on your fix too

knugent · September 12, 2015, 06:28 PM

Boogie man, I was able to pull the "cap" part of my valve off by removing the 4 machine screws holding it on. Under the cap was a diaphragm made of fiber material that had a metal "tit" protruding from it. I took this to NAPA but they didn't have one with the "tit". The one they had was a rubber diapragm. I installed it today, but now I am not getting gas to the engine. I can hear the fuel pump running so it is ok. Is this valve normally in the closed position and is the regular diaphragm not opening it? Where were you able to get the kit for yours? I can see that the only way I can access the entire valve is by dropping the tank. I did that to replace the fuel pump and had rather not do it again. Mine is a 89 Winnie Chieftain with 454. Thanks for any help or insight that anyone can give me. I realize that this is a fairly old thread, but I'm hoping someone is still following it.

Rickf1985 · September 12, 2015, 06:41 PM

Did the diaphragm you got have a metal center for the spring to ride on and did you put the spring back in?

DaveVA78Chieftain · September 12, 2015, 07:02 PM

Holley 12-807 Regulator repair kit

Regulator Rebuild thread

boogie_man · September 13, 2015, 03:28 AM

Got my kit from oreilly's, there's a flathead screw with a lock nut you need to set for correct fuel pressure flow ?

knugent · September 26, 2015, 04:46 PM

Rick, thanks for the reply. I see my problem. When I removed the cap from the regulator, the spring had fallen out and I didn't realize it. Since then, I ordered the Holley kit and it came in a couple of days ago. It didn't come with any instructions, so I have questions:
1. Does the spring go under the cap or inside the valve? Did you use the hp spring or the lp spring?
2. Does the side of the diapragm with the "tit" go under the cap or inside the valve?