Cheap ($18) hot water circulating pump -- anyone want to try using for aux pump? - PeachParts Mercedes-Benz Forum

renaissanceman · #1 05-19-2015, 05:04 PM

I was thinking on my eventual redneck solar/waste oil powered hot tub (

) and was looking up hot water circulators, and lo and behold:

Solar DC 12V 24V Hot Water Circulation Pump Brushless Motor Water Pump 1000L H | eBay

or:

http://www.ebay.com/itm/Solar-DC-12V-Hot-Water-Circulation-Pump-Brushless-Motor-Water-Pump/171357570920?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D29907%26meid%3Da179b363896a4661a8677e2328b7 537f%26pid%3D100005%26rk%3D1%26rkt%3D6%26mehot%3Dag%26sd%3D181722213253&rt=nc

Which got me thinking on the high cost of the aux pumps on these cars. It has 1/2 inch inlet/outlet fittings, so it will be just about a perfect fit.

jay_bob · #2 05-19-2015, 05:10 PM

It's only rated for 100 deg C water, and does not say it's good for glycol.

Not willing to chance my cooling water on this...

renaissanceman · #3 05-19-2015, 05:12 PM

Yeah, but if someone has a beater and wants a project...the coolant should not be over 100C often, right?

renaissanceman · #4 05-19-2015, 05:16 PM

The second one is made of PPS plastic, which according to this publication is completely compatible with ethylene glycol.

HappyHappy · #5 05-19-2015, 05:23 PM

Quote:

Originally Posted by renaissanceman

Yeah, but if someone has a beater and wants a project...the coolant should not be over 100C often, right?

What is the potential cost of a failure? Looks like you've got a OM603 with an alloy head, a no-name cheap plastic pump with a claimed 100C upper temp limit sounds like a quick way to a $2000 cylinder head overheating event, all to save not even a hundred dollars? Bosch 001-835-13-64, listed on Peach Parts for $90 and Amazon for $55 and up

Coolant temps can easily get over 100C in traffic, climbing a grade etc.

renaissanceman · #6 05-19-2015, 05:48 PM

Quote:

Originally Posted by HappyHappy

What is the potential cost of a failure? Looks like you've got a OM603 with an alloy head, a no-name cheap plastic pump with a claimed 100C upper temp limit sounds like a quick way to a $2000 cylinder head overheating event, all to save not even a hundred dollars? Bosch 001-835-13-64, listed on Peach Parts for $90 and Amazon for $55 and up

Coolant temps can easily get over 100C in traffic, climbing a grade etc.

Yeah, like I said, I have a brand new one in my car, and am not planning to use it. Just throwing out ideas. Didn't realize this would start a firestorm. Sorry I brought it up.

HappyHappy · #7 05-19-2015, 06:11 PM

Quote:

Originally Posted by renaissanceman

Yeah, like I said, I have a brand new one in my car, and am not planning to use it. Just throwing out ideas. Didn't realize this would start a firestorm. Sorry I brought it up.

I don't think it's a firestorm, just people responding to aspects that maybe weren't fully considered, that's all. Completely unrelated, but there are now a wide variety of DC powered small pumps that perform perfectly for irrigating clandestine medicinal crops using drip emitters though! A pump, a PWM controller, digital timer and the Li-ion 12 volt battery and great things can happen.

renaissanceman · #8 05-19-2015, 06:17 PM

Quote:

Originally Posted by HappyHappy

I don't think it's a firestorm, just people responding to aspects that maybe weren't fully considered, that's all. Completely unrelated, but there are now a wide variety of DC powered small pumps that perform perfectly for irrigating clandestine medicinal crops using drip emitters though! A pump, a PWM controller, digital timer and the Li-ion 12 volt battery and great things can happen.

Yeah, I was thinking along those lines once too. The crops I was considering were clandestine rhubarb and wild berries up in a (wet and cool) microclimate in a tiny valley in the sierras with a stream running through. I got the crops planted, and then the drought hit, the stream dried up and they all died. That location would be perfect for weed, too though!

Were I to get a really crappy MB (like that 700k mile one in austin) I'd definitely try the cheap pump, and just keep an eye on the coolant level. The plastics it is built with are pretty chemically and thermally stable. On another sidenote, I've got the old pump from my 300D laying around, maybe a new motor can be sourced to cheaply rebuild them.

charmalu · #9 05-19-2015, 11:04 PM

The first pump the seller is in Hong Kong and the second listing
the seller is in Shen Zhen, China.

Wonder why these Aux pumps were not installed on the 240D?
When she idles for a bit, there is cool air coming out of the vents.

Using WVO to heat the Hot Tub is a cool idea.

Charlie

renaissanceman · #10 05-20-2015, 12:18 AM

I don't mind the sellers being foreign...I buy a lot of stuff that ships from Asia if I have the time to wait (mostly electronic components and such) -- it's usually the same things you find from US sellers, but cheaper without the middleman. Some Chinese made stuff is very high quality these days...much of the world's innovation is going on over there now, unfortunately.

Quote:

Originally Posted by charmalu

Wonder why these Aux pumps were not installed on the 240D?
When she idles for a bit, there is cool air coming out of the vents.

Using WVO to heat the Hot Tub is a cool idea.

I don't know why there is no pump on the 240s, but I imagine one could be put in pretty easily if you lived in a cold climate and needed it.

I was actually going to use motor oil since I ususally have a jug or two on hand. The system would be set up to use solar during the day to maintain temperature using an array similar to this one:
http://rimstar.org/renewnrg/solar_pool_heater_diy_fp.htm
with thermistors and PWM to keep the outlet temperature above the tub target temperature by controlling flowrate through the array. Then use the oil burner for nighttime or cloudy winter days.

vstech · #11 05-20-2015, 08:19 AM

Another flaw with this pump as an aux pump would be pressure... The cooling system has over 20 psi on it until the cap burps... What is the cheap pump rated for? The garden hose connections make me think it's designed for lift use only... Could it work? Sure...

JamesDean · #12 05-20-2015, 12:39 PM

I think I paid $60 for the new one in my 91 300D...They aren't that expensive...unless they've gone up in price..

I have seen Bosch aux water pumps for Audi's in that price rage...looked awfully lot like the MB variant.

renaissanceman · #13 07-22-2015, 03:30 AM

I picked one up to play with for the solar hot tub. It is surprisingly well made, actually.

m1tch · #14 07-22-2015, 07:34 AM

Fit a Davis Craig pump.

Zacharias · #15 07-22-2015, 10:26 AM

Quote:

Originally Posted by JamesDean

I think I paid $60 for the new one in my 91 300D...They aren't that expensive...unless they've gone up in price.

On PP, you currently have a choice of MTC for $81.25 or OE for $678 (cough, gag).

Given the MTC track record on the monovalve inserts, I wouldn't be excited about this choice....