Jump to content

Leaking Water Pump - Shurflo Trail King 7


Recommended Posts

We have heard a knocking in the water supply with the pump kicking in every few seconds, we've located the fault and it seems that there's a leak from the pump.


I have no experience of things watery and so I wonder if anyone could help me identify which part needs to be replaced and whether I can do it myself.


The leak is coming from the top of the pump and is spurting out of the bottom of the two cables. Is it time to replace the pump entirely or is there a spare part that I could use instead?




Link to comment
Share on other sites

If you are happy to install a new pump anyway, why not remove the old one and carefully take it apart to see if the cure is a simple one or if a new pump is needed after all?

You have nowt to lose and potentially the cost of a new pump plus the experience of knowing how a pump works to gain.

The two wires look like they may be the contacts for the pressure switch that tuns the pump on and off and this part is available online as is lots of Shurflo pump info, parts and diagrams.

Link to comment
Share on other sites

Guest pelmetman

I changed mine, its pretty straight forward if you have the arms of a orangutan 8-) ........


But as mentioned make sure you swap like for like ;-) .........





Link to comment
Share on other sites

SHURflo pumps and spares are advertised here




There are only two “Trail King 7” pumps - a 20psi version or a 30psi (wih the former probably the most commonly fited to motorhomes).


If a damaged pump has some age it will make sense to replace it as Keith has advised. Besides which (as will be evident from the advert) the spare part ‘kit’ needed to repair an elderly leaking pump may cost 50% of the price of a brand-new pump.


As Tracker suggests, it would be worth examining the faulty pump to see if the leak can be addressed at no cost (eg. by tightening loose screws) or if there is actual damage (eg. a cracked plastic head/housing.)




Link to comment
Share on other sites

  • 6 months later...

I've had a leak from the casing joint on my Motorhome Shurflo Trailking pump and ordered a new one on Monday - it arrived today (Thursday) and was fitted in an hour.


I changed the pump rather than repair the old one because the only way we knew the pump was leaking was when water seeped under the habitation seats while we were in Belgium – and potential damage to the seat carcasses and floor could be more costly than the £50 replacing the pump


Is there some kind of sealant that could be used to fasten the 'old' pump casing segments together and use as a spare if required in the future ?

Link to comment
Share on other sites

The major components of a SHURflo Trail King pump are shown in the attached drawing below.


Whether it’s possible to prevent your original pump from leaking using sealant/adhesive is likely to depend on why it leaked. I don’t think you’ve ever provided details of your motorhome, but if it’s getting on in years and the leaking pump is original, it may be that the leakage is through a worn-out seal between the pump’s head-unit and the motor’s drive-shaft - and you won’t fix that with sealant.


No sealant is used when these pumps are assembled, with everything held together by a few screws that pass through the head-unit’s plastic casings and attach to the motor’s body. The only way to decide how realistic a ’sealant repair' might be would be to disassemble the pump and identify why it leaked.


If you decided that a ’sealant repair’ should be effective, you’d really need to test-run the pump for a significant period after the repair had been done - but even then you’d be risking the pump leaking again if you ever found it necessary to install it back in your motorhome.


Link to comment
Share on other sites

Derek, thanks for the info.


The pump is around 6 years old and the leak which only becomes apparent when running the pump is at the point of the arrow where the two casings join.


There is a 'whitish' powder, that rubs off easily, where they join and tightening all the screws made no difference to the small leak.


I read somewhere (possibly on a thread on these forums – although I couldn't find it) that a smear of Hylomar Blue would create a seal between the casings and has helped other people continue to use their original pumps.


I have now fitted a new pump but wondered if the 'old' one could be used as a spare in any future emergency – I hate chucking things away that may be useful later.


I have a Black and Decker drill that was working 'intermittently' that I bought off a Market Stall for £2 back in the sixties – it's still working very well even now.


I'm not trying to save the Planet – I'm just tight fisted …...


Link to comment
Share on other sites

Hylomar products have never been referred to on the Out&AboutLive forums, but were mentioned in a 2013 MotorHomeFun discussion about a SHURflo water-pump leak




“Captain Tolley’s” has occasionally been recommended here for addressing minor water leaks through windscreen seals, etc.




but I’m doubtful that appying this to the pump externally (or applying Hylomar Universal Blue externally) would be reliably effective.


If you were to use Hylomar Universal Blue, you’d need to disassemble the pump first (as stated in the MHFun forum thread) at which point you might be able to detect the cause of the leak.


Having taken apart a Trail King pump I don’t recall any gaskets being present between the plastic sections, with watertightness being achieved via the design of the internal components within the plastic casings. So a water leak through the joint arrowed in your photo suggests that there’s an internal fault (or that there’s an ‘invisible' crack in the plastic casing at the joint).


Take the old pump apart and diagnose the reason for the leak. If it’s evident that an internal part has become damaged or that the casing is cracked, you’d need to decide whether the cost of buying a replacement part would be worthwhile. If there’s no sign of damage, try the Hylomar ‘fix’.

Link to comment
Share on other sites

I have had a similar leak twice. On both occasions (several years apart) it was caused by freezing a tiny amount of water remaining in the pump head even after draining the system and blowing out.

I have replaced the pump as the replacement head plus postage (as previously stated) was > 50% of the cost of new.

When I'm laying up the van with no heating and possible frost I now thoroughly drain down the system and then disconnect the pump ( John Guest fittings either side). I loosen three of the mounting screws, rotating the pump through 90o. I always find 20 to 40mls of water remaining in the head which would be enough to freeze it and crack the head.

Is it a pain- of course- but it only takes 10 mins and now I don't lose any sleep.

There's nothing worse than planning a weekend away then finding there is no water !!


The wife's not so keen on a "dirty weekend" these days......

Link to comment
Share on other sites

The YouTube video here



may be of interest as it shows a leak from the same place as on Roryboy’s SHURflo Trail King pump, with the suggestion that the cause lay with the diaphragm within the pump.


FWIW it’s now possible to obtain a ‘strainer’ and connectors with wing-nuts (examples in attached photos) that avoid the need to employ spanners on the plastic fittings.



Link to comment
Share on other sites

Derek - Thanks for that helpful info.


New wing nuts came with the new pump and there was already the strainer fitted.


If, as the guy says, that the diaphragm is probably the problem then I'll keep the old pump as emergency spare but won't bother doing any other work on it.


Again, thanks

Link to comment
Share on other sites

When there was a problem with my Rapido’s water system last year (mentioned in this link)




I sourced a replacement SHURflo pump from here




as the strainer and connectors would be provided and I wasn’t certain where the problem lay. (In fact, not with the pump at all :-( )


The pumps do dissassemble and reassemble quite easily, so you might consider taking your old pump apart as there’s little value keeping it as an ‘emergency spare’ if it leaks badly. A replacement diaphragm drive kit costs £25-£30.




(Evidently the pump does have is a gasket - between the plastic head-unit and the motor casing - though I don’t remember noticing this when I pulled my pump apart.)


Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Create New...