Leak at back of Raw water impeller housing?

[Zippysigma]

Hi, I replaced the impeller on my Volvo 2020 at the start of the season and have had a drip from the housing ever since. I assumed that it was from the gasket.

It is getting steadily worse - 1 bucket full after an afternoon's motoring this weekend.

Looking closely, it appears to be coming from the back of the impeller housing from some holes in the casting, not from the gasket.

Any ideas? is there a seal in the pump that leaks? Can i service it?

Thanks in advance

 

[johnphilip]

me too

I have the same problem with the same model Volvo, so suggestions please, I have a nasty feeling it may be time for a new water pump, at volvo prices.

 

[BobnLesley]

Impellor leaks

It sounds like ours on an MD6A:

The impellor is driven via a shaft from the engine, which has two seals on it, fitted within the impellor housing; both face inward (one holding the impellor water back and the other the engine oil) between the two there's a small 'tell-tale' hole in the impellor housing which allows any oil, or more usualy water leaking past the seals; I'm presuming that's where your drip's coming from?

Before you rush of to your local Volvo dealer for replacements, I'd advise that ours uses 1" x 1/2" x 1/4" R23 oil seals, which from Volvo are about £6 each; alternatively, if you visit your local bearing/seal factors, they're about £0.75 each!

On ours, the procedure is: Turn off the inlet seacock, disconnect the water hoses to/from the impellor, undo the two bolts which hold the impellor housing to the engine, remove impellor housing completely, open the front of the impellor housing and remove the impellor complete with the shaft, pop the seals out of the housing and replace, then re-assemble and re-instate. On ours the job takes about 25 minutes from start to finish.

 

[VicS]

The hole from which the water is leaking is a weep hole designed to allow water which has leaked past the water seal to escape rather than find its way past the oil seal and into the crankcase.

Replace the seal before the leak becomes so bad that the water does get into the crankcase

In fact replace both seals, inspect the bearings ( they will be the first to suffer if any water gets through the oil seal) and also the pump shaft for wear where the seals run. If necessary replace the shaft as well.

Link to workshop manual http://www.bluemoment.com/downloads.html

 

[BobnLesley]

Yep. that's the one

"...also the pump shaft for wear where the seals run. If necessary replace the shaft as well."

It's due to a worn shaft that ours leaks regularly - we do the seals about every 100 hours, which for us is usually twice and occassionally three times each season; a PIA, but at £1.50 a time, it's a cheaper option than the £60 we got quoted for a replacement shaft!

 

[Malish]

worth 'upgrading' to viton seals - they cost a few pence more but are more tolerant of salt water.

 

[rogerthebodger]

And do specify the seal is for water as a different spring is fitted when the seal is used for water than when it is used fir oil.

 

[Scotty_Tradewind]

My shaft seals went on my impell'r pump too.
Took me ages to realise where the drip was coming from.
The speedseal cover did help reduce the amount of time though.

 

[brianhumber]

Try to get the seal number yourself and then get a seal yourself from a factor. You will be surprised at how cheap they are and you can then in good humour with a glass of what you fancy to hand reflect on Volvo dealer markups.

Changing seals is not difficult, but have a look at the surface of the shaft, if very ridged then a new shaft might be needed. If Volvo want a lot, you can have a new shaft made up at a engineers normally a lot less. Again further opportunity to reflect on so called Volvo quality, design and mark up.


Brian

 

[Zippysigma]

Impeller leak advice - thanks

All who replied, these are excellent responses as usual thanks.

As long as the shaft is ok, it looks as if my worst fears should not be realised!

I will strip it down and take a look.

Can you get Viton seals from factors as well as from Volvo?

Happy sailing.

 

[TradewindSailor]

Being in an area where boat parts like pump shaft have to be imported from the USA at vast expense and time, or made locally; I tend to make the original shaft last as long as possible.

The shaft gets grooves in it mainly due to the exclusion of oxygen where the seal touches which would normally protect the stainless steel. I have found that I can extend the life of the shaft by turning it in an electric drill and dressing the shaft with a needle file and emery cloth in order to make the groove less prominent. It works. It also works for propshafts if you can find a way to turn the shaft ...... but perhaps a machine shop would do a better job.

I am not familiar with Volvo pumps though.

 

[Zippysigma]

Sea of Cortez

I have sailed in the Sea of Cortez - i can fully understand why you need to be self sufficient!

 

[LeonF]

I have the same problem with the same model Volvo, so suggestions please, I have a nasty feeling it may be time for a new water pump, at volvo prices.

I have been sourcing pumps for a 2010. Get a Jabsco from Jabsco Shop direct ( the Volvo is a Jabsco) and save yourself a heap of money, or try Mack Engineering and you may get it even cheaper.

 

[Tex]

Resurrecting an old thread but suspect I have a small leak at the back of this pump.(MD2030C),
If I purchase the shaft service kit how easy is it to replace the seals? Are any special tools needed? Would prefer not to have to buy whole new pump.

 

[villager]

I have a Volvo 2003 that has had the same problem. Assuming it is the same pump Keyparts do a refurbishment kit for about £40 that includes the shaft, seals (& bearings I think.) Might be worth giving them a call if your shaft is showing signs of wear.

 

[slipknot]

Taz. Just buy the seal. A couple of quid online/delivered. 20 mins to fit.

 

[Tex]

Thought about just replacing the seal but do you have to remove the pump and shaft to do this?

 

[Momac]

Not sure using non volvo penta seals is advisable to save a very few pounds. But new seals certainly fixed the leak on my pump.

 

[Quandary]

Thought about just replacing the seal but do you have to remove the pump and shaft to do this?

Some people take the water seal out in situ by pulling it out of the impeller housing but unless you pump is in a really awkward position it is not hard to take it out and do it properly, less risk of scratching the houdsing? There is a circlip behind the second bearing which you remove, then it is not difficult to tap out the shaft complete with bearings, I use a bit of hardwood over a gap in the Workmate. If you do it this way you can replace the oil seal at the same time and check the condition of the bearings. The seals go on back to back with a spacer to maintain a drainage gap between them. If you google 'Compass Marine' they have an excellent technical site on yacht maintenance tasks which details how to do this, in their illustration it is a Johnson pump but most raw water pumps are the same.
Compass Marine site is called marinehowto.com.

 

[Tex]

Thanks for your help.
Will the shaft remove when tapping from impeller end and with the engine gear still connected to the shaft? How easy is it to remove the bearings and seals from the shaft? Sorry for all the questions but I want to know what I am taking on if I proceed.