Changing a water pump

[crob]

Has anyone changed a water pump in a Hymer S class motorhome? I am trying to change mine, and currently I have two problems. Firstly, the water pipe is crimped where it fastens to the pump outlet – how do I uncrimp it? Secondly, there is very little headroom between the water tank outlet and the underneath of the van floor to withdraw the pump unit. If anyone has done this job and can give me any tips, I would be most grateful. It’s like most things with motorhome maintenance – it seems impossible until you know how – then it’s easy! Thanks in anticipation. Colin Robinson. (?)

[Guest aido]

Colin I changed the waterpump earlier this year in our Knaus MH. If there is enough slack on the water pipes to the pump you can cut them off with a hacksaw close to the pump. when fitting to new pump just use dublee clips to hold them tight. dont know about headroom. just watch where the wires go when disconnecting old pump....aido

[JohnP]

Does the waterpump pipe and electical connection go through a large 3 inch diameter fitting which is screwed onto the top of the water tank? If this is so then this will need unscrewing to gain access to the pump. Once this has been removed the pipe can be unclipped from the pump. Do not cut/shorten the pipe which is within the tank itself otherwise the pump will be too high and not reach the bottom of the tank. Crimped clips can be a pain and are virtually impossible to undo without cutting them off. Use a hose clip as has already been suggested as a replacement. This is how the pump is fitted to my Hymer - but designs change over the years. Hope this helps.

[Dave Newell]

Hi Colin, I thought I'd replied to this a couple of days ago but apparently not, must be an extended senior moment. Anyway, I replaced a water pump on a Hymer S class earlier this year for a customer, a nice easy 20 minute job. Remove the large access cap on top of the tank and you can then withdraw the submersible pump easily. Cut off the crimped pipe fittings and replace them with worm drive hose clamps (jubilee clips) but make sure you use stainless steel ones or you'll get rust in your tank. D.

[docted]

Another seal would be a prewarmed cable tie, in a jug of boiling water for two minutes, pulled very tight as it cools it will contract and give you a good seal. Docted

[michele]

Docted, Nice little snippet of info there good idea ;-)

[mover]

Ive had trouble with my Hymer water pump in the past IE it coming adrift from the hose in the tank,what a pain when youve got a full tank of water as you have to open the top of the tank to put your hand in the water to pull the drain plug out of the bottom of the tank and if the tank is overfilled as mine was ,then youve got problems, I had a new pump fitted when my van was last serviced and it came adrift about 3 months later and I found that it was only pushed onto the hose in the tank no clip of any kind was used and I believe this is common Hymer practice,but if it happens again I will use the heated cable tie tip,a great tip I thought many thanks. *-) *-)