200TDI water pump STC639


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So I am driving along yesterday, battery light turns on followed by truck getting hot. Pull over, Alt/WP belt snapped (1 year old Dayco made in P.R.C.). OK whatever, get a ride from my buddy, get another belt that fits at parts store, install new belt, on my way.

This morning I am checking things out and notice that the Bearmach water pump I installed over the winter has some play in the bearing. This thing has maybe 1500 miles on it? I don't remember it having this much play originally so I am thinking the bearing is on its way out. I will try to put a video up for more clarity, the play isn't major but I can hear it knocking a bit.

Does anyone have a source for a better made water pump? The only thing I am seeing via the major players is Britpart, Bearmach, or OEM which is $300. I think $300 for a water pump is insane.

I think I have found 2 other alternatives, Airtex and Blue Print (Bilstein)



Blue Print


Any advice on this? Do I chance it again with another Bearmach? Or try one of these others? Do I swallow a couple Advil and spring for the OEM?

Swapping out the water pump isn't a huge deal, but it still takes a couple hours, makes a mess, and costs about $40 between coolant, RTV and gasket. Also I don't know if this contributed to the belt snapping to begin with, had I not been 10 minutes from home it could have been a real hassle.

$145 shipped for the Blue Print brand vs $185 for Airtex

Surely Land Rover doesn't manufacture there own pumps. Does anyone know who makes the OEM? I see some mentions that Airtex might make the OEM.

Anyone know the difference between STC635 (2.5TD) vs STC639 (200TDI) pump? Pictures look same, and I see some places show them as interchangeable.


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Had Zack special (proline) a couple years ago has been fine, but also carry a spare in the deep locker I made jusin case mode.


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After doing a bit of research I see some UK guys saying they have had issues of Defender 200's snapping the belt due to the belt being a tiny bit wide. OEM belt is 11mm wide x 1025mm long. They have switched to 10mm belt with better luck.

Napa has a 25-7405 XL USA made belt that is 19mm longer, no issues, and 10mm wide, retail was $25 the sales person did it for $15. Hopefully that helps out.




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It also looks like part number STC637G might work but not have the hookup for the fan (I have electric).

If so Britpart has their "high end" UK made "Pro Flow" model that is only $62. I kinda found it weird that they would make their performance pump for their least performance engine.

STC637 is supposed to be for 2.5 Diesel non turbo w/o a viscous fan

The gasket is the same for STC635, STC637, STC639 part number ERC5655

The castings look the same.

Anyone have a picture of a pulley for 2.5 diesel for pump PN STC637?


Anyone have an STC637 they can compare to a STC639?




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OK looks like the pulley is the same between all 3 models, ETC4785

I think I might pull the trigger on the Britpart XS Pro Flow @ $55


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This is the manufacturer for the Britpart XS Pro Flow

"Mark Water Pumps Ltd is a water pump manufacture for the automotive industry, for passenger and light commercial vehicles. Mark Water Pumps aftermarket manufactured range covers 90% of the European car park by volume. MWPL also manufactures OE water pumps for Aston Martin, Jaguar, Land Rover, GM and Volvo.

The Pro Flow water pump range is manufactured in-house by Mark Water Pumps from its 100,000sq ft factory which includes casting, machining, assembly and testing facilities. The team has many years’ experience manufacturing water pumps for OE and Aftermarket use and the product range has grown to incorporate over 500 part numbers which support many of the vehicles on British roads today."


Part numbers-

17J (non turbo diesel?) - MWP2580
11L 200TDI - MWP3309
16L 300TDI - MWP3496

EDIT ---

"JLR may have ceased production of the Land Rover Defender with the last one rolling off of the production line in 2016, but Mark Water Pumps certainly hasn’t stopped making its vital components. The company, which supplied the original equipment water pump for 16 years from 1990 has been checking through its aftermarket back catalogue and has established that it can still supply water pumps to cover an amazing 43 years of the vehicles 68 year history."



Technical Excellence Contributor
Thanks for the info. When I need it, these are the types of threads that save me hours of searching.


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I am going to contact Mark's and ask them if they can tell me the difference between 17J (non turbo diesel?) - MWP2580 & 11L 200TDI - MWP3309. Suspect it is just the snout. I will ask them where I can get an MWP3309 just in case as well. I don't see that Britpart carries the MWP3309 but will check just in case.

"Keeping with the Welsh connection, Mark Water Pumps Ltd based in Colwyn Bay, Wales has a long history in producing Land Rover parts, having produced the OE water pump for the Defender over a 16 year period from 1990 to 2006 and providing the aftermarket with a wide range of Land Rover water pumps through our Pro Flow range.

The Pro Flow range of automotive water pumps is manufactured in the same factory as the OE pump, so design, quality and availability is assured. For the Defender range the following are available as OES parts"



Technical Excellence Contributor
Good find dude, my britpart one has been going strong for 7 years! Next tb change I'll try one of these


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I will try one next time round too.

Just swapped a britpart one onto the car after last pump failed, already leaks a bit from the relief hole wtf.

My new spare is also a britpart, ran into the same issues as everyone else trying to find a good quality pump...


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Still waiting on Mark's to get back to me. I emailed them yesterday. Hopefully we can get ourselves a good affordable reliable water pump


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Heard back from MWP today. Total Defender enthusiasts. 100% in house manufactured in the UK. 32GBP ($45) + shipping. Say goodbye to Chinese water pumps. You can order direct from them. Contact David Lewis at david.lewis@mwpl.eu

Anyone local want one? We can split shipping


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Pump arrived today. Looks nice from what I can see. I will try to compare the Bearmach when I get it off. Hoping to get it installed later today.





Technical Excellence Contributor
diggin this one back up. Thanks @AdamSanta85 for the legwork..im sure you are still out there lurking.. ;)

Anyone have a good source for the proflow pumps? I know I can go direct, but wondering if anyone can confirm a stateside supplier of the britpart boxes or Marks. Happy to split shipping up if anyone needs a 200 or 300 tdi pump.