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Randall, RVIA Certification
Category: RV
Satisfied Customers: 10332
Experience:  RVDA/RVIA Master Certified Technician with many years experience.
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I have a 5th wheel Montana mountaineer, not sure the year

Customer Question

I have a 5th wheel Montana mountaineer, not sure the year but I think 2002. It has 2 slide rooms, the bedroom and the main slide in the living room. The rooms both come out perfect, bedroom retracts slowly and main slide will not go in at all. It has a dewald hydraulic pump. Please help.
Submitted: 2 months ago.
Category: RV
Expert:  Randall replied 2 months ago.

Hi! My name is ***** ***** I can assist you with this. I may need some additional information from you first in order to give a complete answer.

Expert:  Randall replied 2 months ago.

One battery or two? Are you plugged into shore power when you to this? Do you have a small digital multimeter for some testing? About $20 or so at most hardware stores and easy to use. That would be helpful here for some testing.

Customer: replied 2 months ago.
It has 1 battery, converter works perfect, shows over 12v, plus I also tried using cables. I have a multimeter, but I don't think the problem is electrical.
Expert:  Randall replied 2 months ago.

Only testing can tell you that. If you only have one battery you are going to have low voltage issues and once that happens the pump won't develop the correct pressure. Happens all the time. I see this question about once or twice a week here. You have to eliminate the voltage issue first and then go for pressure issues. Since you said you replaced both solenoids, that pretty much eliminates that as a cause. The pump may not be developing enough pressure, but is that due to low voltage or not? Testing is need to find out.

Customer: replied 2 months ago.
What do I need to test, both the green and blue wire going into the pump motor receive over 12v.
Expert:  Randall replied 2 months ago.

No...........the main cable to the pump relay. That should be a heavy red cable. You want to see over 12.5 VDC under load.

Customer: replied 2 months ago.
Shows 13.6 with jumper cables on it, 12.7 without.
Expert:  Randall replied 2 months ago.

Jumper cables from where?

Expert:  Randall replied 2 months ago.

Does the pump perform when you do that or not? If not, then it is suspect on the pressure it is developing and only installing a pressure gauge would really tell you that.

Customer: replied 2 months ago.
What should the pressure be? Does the gauge install where the plugs are? There's 1 plug on the up(extend) side and 1 plug on the down(retract) side. They take a hex bit to remove.
Expert:  Randall replied 2 months ago.

It usually goes on a tee inserted into the line. You should see something over 2500 psi. This varies with the system. If you can give me which one you have I can give you more.

Customer: replied 2 months ago.
It's a dewald pump with Parker motor. No solenoid valves, all mechanical. No external manifold, lines come right off the pump.
Expert:  Randall replied 2 months ago.

Then you have to remove that line at the pump and install a tee with the pressure gauge. That would tell you the story.

Customer: replied 2 months ago.
Pressure is low, I'm attaching a picture, need to know if that is the adjustment screw?
Expert:  Randall replied 2 months ago.

There is no adjustment for the pressure. They are designed to work at one pressure for that system. How low was it?

Customer: replied 2 months ago.
I meant for the relief valve, after rebuilding the pump I'm petty sure that's the relief valve, but I didn't want to move it so i left it alone. Pressure was at 1900... Unless I tested it wrong, but I don't think so cause it's pretty straight forward.
Expert:  Randall replied 2 months ago.

Not sure, as we always replace a pump that is bad. And that was too low for sure!

Expert:  Randall replied 1 month ago.

Just checking back in to see if you were able to resolve this issue as I hadn't heard back from you. If not, and you still need additional input on this problem please get back to me. I will make a phone chat offer for you as well in case you fell that might be more helpful.