As you’ll see from the photos below the water pressure pump is a stubborn little 12 volt affair that’s bad mannered and NEVER does as it’s told. Ours has had the equivalent of the terrible twos since we got our Autotrail Apache 632 in September 2019.
A brief description for those that are curious will, I hope, suffice. The pump is designed to pressurise the fresh water tank to 20psi (about 1.4 bar) so that when you operate a tap, or the shower or the toilet flush the water is forced out of the tap by the pressure in the tank. The pump kicks in immediately you operate the tap in an attempt to re-pressurise the tank. Our little sod would work 9 times out of 10, but occasionally it would not fire up. I applied the brute force and ignorance, coupled with a little well meaning rage and a short length of scaffolding pole, method and all was soon restored to order. Then lockdown reared it’s ugly head..... No trips out for three, nearly four, months. Now the little b*****d won’t switch off after you turn off the tap! Infuriating! Applications of the scaffolding pole left it intransigent and refusing to co-operate.
Right! Time for the application of some science! A new pump is around £80, so what’s the worst I can do if I take the original to bits?
Intuition lead me to believe that the pump has a faulty pressure switch, my knowledge of motors and pumps made me concentrate on the wiring into the bottom of the pump. I slightly undid the three screws holding a black plastic box to the bottom of the pump, oops! Rush back into the MoHo and turn the electric tap switch on the control panel to “Off” Return to the scene of the crime and the water’s stopped peeing all over the garage floor! Note to self.... remember never to work with animals, children or live electrical systems..... Anyway the water had stopped escaping so I unwound the screws the rest of the way, undid the wiring and removed the black box for inspection.
My multimeter proved that pressing the pressure switch created continuity through the two terminals that the removed wiring had exposed. It worked every single time the pressure switch was activated. The people on eBay want to sell you a micro-switch, which is one of only two moving components in this little contraption, they want at least £5 for it, it’s worth at the most 20p. I took the assembly completely to pieces and inspected the micro-switch, it’s in perfect working order, I next looked at the pressure spring, perhaps a little sticky in it’s housing? Cleaned the housing with some very fine emery paper.
Re-assembly is pretty straight forward, tighten everything up, check everything is watertight then turn on the tap, turn off the tap, PUMP STILL RUNNING!!
Took it all to bits again and noticed a very small 2mm grub screw below the the pressure springing the underside of the housing, I had a hell of a job getting an Allan key into it as it looked like someone had been there before me with a screwdriver, I loosened it half a turn anti-clockwise, re-assemble.
Robert’s your Mother’s Brother!
Works like it should have done right from the start.
Mrs. A is very pleased, this means that when I go for a pee in the middle of the night and flush the bog she no longer has to leap, scantily clad and torch in hand, to the garage door, fumble with the locks, drop the keys in the long grass, bash the pump with the scaffolding pole, waking up the rest of the campsite and drawing the wrath of the warden, then tripping over the dogs lead and falling face first into the long, wet, grass before returning to our marital bed, yes, very pleased!
So for all you funsters out there with a shurflo water pressure pump, fiddle with the Allan headed grub screw before you by any new components or a new pump!!
Cheers!
Russ
The pump
The Allan screw is the only circular item in the picture that isn’t obviously a screw head.
A brief description for those that are curious will, I hope, suffice. The pump is designed to pressurise the fresh water tank to 20psi (about 1.4 bar) so that when you operate a tap, or the shower or the toilet flush the water is forced out of the tap by the pressure in the tank. The pump kicks in immediately you operate the tap in an attempt to re-pressurise the tank. Our little sod would work 9 times out of 10, but occasionally it would not fire up. I applied the brute force and ignorance, coupled with a little well meaning rage and a short length of scaffolding pole, method and all was soon restored to order. Then lockdown reared it’s ugly head..... No trips out for three, nearly four, months. Now the little b*****d won’t switch off after you turn off the tap! Infuriating! Applications of the scaffolding pole left it intransigent and refusing to co-operate.
Right! Time for the application of some science! A new pump is around £80, so what’s the worst I can do if I take the original to bits?
Intuition lead me to believe that the pump has a faulty pressure switch, my knowledge of motors and pumps made me concentrate on the wiring into the bottom of the pump. I slightly undid the three screws holding a black plastic box to the bottom of the pump, oops! Rush back into the MoHo and turn the electric tap switch on the control panel to “Off” Return to the scene of the crime and the water’s stopped peeing all over the garage floor! Note to self.... remember never to work with animals, children or live electrical systems..... Anyway the water had stopped escaping so I unwound the screws the rest of the way, undid the wiring and removed the black box for inspection.
My multimeter proved that pressing the pressure switch created continuity through the two terminals that the removed wiring had exposed. It worked every single time the pressure switch was activated. The people on eBay want to sell you a micro-switch, which is one of only two moving components in this little contraption, they want at least £5 for it, it’s worth at the most 20p. I took the assembly completely to pieces and inspected the micro-switch, it’s in perfect working order, I next looked at the pressure spring, perhaps a little sticky in it’s housing? Cleaned the housing with some very fine emery paper.
Re-assembly is pretty straight forward, tighten everything up, check everything is watertight then turn on the tap, turn off the tap, PUMP STILL RUNNING!!
Took it all to bits again and noticed a very small 2mm grub screw below the the pressure springing the underside of the housing, I had a hell of a job getting an Allan key into it as it looked like someone had been there before me with a screwdriver, I loosened it half a turn anti-clockwise, re-assemble.
Robert’s your Mother’s Brother!
Works like it should have done right from the start.
Mrs. A is very pleased, this means that when I go for a pee in the middle of the night and flush the bog she no longer has to leap, scantily clad and torch in hand, to the garage door, fumble with the locks, drop the keys in the long grass, bash the pump with the scaffolding pole, waking up the rest of the campsite and drawing the wrath of the warden, then tripping over the dogs lead and falling face first into the long, wet, grass before returning to our marital bed, yes, very pleased!
So for all you funsters out there with a shurflo water pressure pump, fiddle with the Allan headed grub screw before you by any new components or a new pump!!
Cheers!
Russ
The pump
The Allan screw is the only circular item in the picture that isn’t obviously a screw head.
