Community Forums

Brian1e · 08-15-2015, 04:26 PM

I have a failed fuel pump in a 1990 Holiday Rambler Alumilite coach/Chevy P30 chassis.

My question is, would it be feasible to cut a hatch to gain access? The tank is located under the master bed with about 6" clearance between top of tank and floor. I really don't want to drain and drop the full 60 gal tank.

BFlinn181 · 08-15-2015, 09:30 PM

If you have access under the bed it might be the way to go, especially if the tank is full. Be aware the floor could possibly be a 'sandwich' of plywood, foam board insulation, then underlayment floor. Check to make sure you're not cutting through wiring or plumbing, a couple of shallow cuts better than one too deep one. Also, if you can, angle cut to make the hatch fall into place, like cutting a lid on a pumpkin.

ahicks · 08-16-2015, 07:49 AM

I know that plan has been done successfully, but no clue on this coach. I just wanted to add to what Bob mentions above, that I'm pretty sure you're going to find steel cross members (angle or tubing) included in that sandwich. Not that cutting through one would be that difficult, but if you could avoid that, I think you would end up with a nicer job that would not adversely affect/compromise the strength of the floor. Maybe a couple minutes with magnetic stud finder would pay off? -Al

Brian1e · 08-16-2015, 08:43 AM

Thanks for the replys. Good points about the sandwich, and potential objects hidden within. I will keep you posted.

DonDee · 08-16-2015, 08:59 AM

I did my old Southwind. Layers= Vinyl floor cover, plywood, foam, sheet metal.

Cut 3 sides on the steel and opened it up AFTER I measured many times.

leadman · 08-16-2015, 11:07 AM

You do want to make sure that when you put the piece of the floor back in you want to be sure it is sealed against any fuel or fumes getting into the motorhome. A thin metal plate put up against the bottom with sealer and screws to hold it would be what I would do. Then seal the cut piece when installing it.

My 1988 Itasca on a P30 chassis has the electric pump in the tank and a mechanical pump on the engine. You might have the same set up.

SafetyPhil · 08-18-2015, 06:27 PM

I merely placed an elect fuel pump at a low point in the fuel line of my class C and tied the power to the ignition and she works fine.

Brian1e · 08-19-2015, 07:18 AM

I considered that, but I heard/read somewhere that GM pumps of that era are positive displacment pumps. If this is true, I would expect it difficult or impossible to draw fuel through the old pump with an external pump.

ahicks · 08-19-2015, 10:41 AM

Pulling fuel pump power from something powered by the key switch can leave you in a world of hurt if something goes wrong. There's a reason there's a oil pressure switch in that circuit.

BA-in-Mich · 08-19-2015, 07:17 PM

I had the pump switch go bad on my "90". I was able to drive 800 miles on the mechanical pump. It didn't like the hills very much or hard acceleration but was able to make it home. ( it did a lot of backfiring under acceleration )
I just got done pulling down my tank and replacing the in tank pump and the hoses. I used a harbor freight hydraulic table to lower and install the tank. I probably had 20-30 gallons of fuel in it. I had to jack up one side of the motorhome about 4" to roll out the tank, dropping and raising was a piece of cake. Finding the correct pump and hose that fed the pressure regulator was more of the chore. I did this as preventive maintenance. With the table a full tank of fuel shouldn't be a problem. ( it's a 1000 lb table )

jorger146 · 09-01-2015, 09:37 PM

I also own a 1990 Holiday Rambler AlumaLite 35 footer wth tag axle. I was able to replace the pump by removing the right rear (tag axle) wheel. There is an opening just big enough to work the comple sending unit with pump out of the tank.