Heater Pump ESPAR Replace Brushes
The circulation pump for the auxiliary or the booster diesel fired heater is known to fail because the brushes wear out or hang up. The circulation pump needs to establish coolant flow through the heater for the heater to fire when the engine isn't running. The brushes can be replaced DIY. rbjenterprises posted this on the Yahoo Sprintervan forum. Thanks goes to rbjenterprises for the follow-up post and to Yahoo Sprintervan.
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20101102 edit:
More info about the
pump and brush replacement can be found here:
Very Technical Espar Question
https://sprinter-source.com/forums/showthread.php?t=8968
A recent brush supply in this post. Thanks goes to rbjenterprises.
https://sprinter-source.com/forums/showthread.php?p=202285#post202285
"I used some dental floss and passed it down the channel next to the brush, over the front of the brush then back out. I clamped the plastic motor end in the vice, pulled one brush up in to its housing and clamped the floss, pulled the other, slipped the motor housing on. Done! It works."
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This is the Yahoo info:
http://autos.groups.yahoo.com/group/sprintervan/message/54034
Here is an update about the circulation pump that caused the problem.
New one got here real fast, easy to replace just clamp off the hoses then swap
out pumps. Works! All I can ask for.
Well now I have the old one. It is broken so what can I lose? Took it apart and
found that the brushes were worn out, 2 winters and 44k miles, not what I would
call a robust design. Does anybody know when this pump actually operates? I know
it does when the REST button is pushed or when the booster heater is running
with the engine off. Does it also work when the engine is running? Either way I
would say if the pump only works with the espar on it only lasted less than 100
hrs.
I found some brushes close to the same size at the local True Value Hardware
store. Soldered them in, finally got it all back together and it works. I guess
it will go on the shelf and wait for a couple of winters and swap out the new
one. The old brushes were labeled L47, I could not find that exact replacement
so the hardware store ones were as close as I could find. The brush springs may
hang up but nothing a whack with a hammer won't cure.
Evidently this pump is a sore spot for other Mercedes build vehicles. I punched
the
part number, 0 392 020 026, into Google and found that the Crossfire uses
this pump to cool its inter-cooler. On their forum they did not like it either,
they found a Johnson pump, CM30, that would replace it. It looks the same as the
Bosch but with a pigtail instead of a plug socket.
I think that the price was close to the price from Eurparts.
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A possible aftermarket replacement pump. (It may even fit the OEM bracket/rubber mount.
https://www.amazon.com/TOPSFLO-Brushless-Auto-pump-circulation/dp/B00QNRUWJ8/
A knockoff pump for about 40 bucks.
cciyu Auxiliary Water Pump fit
https://www.amazon.com/cciyu-Auxiliary-Mercedes-Benz-Freightliner-0392020026/dp/B07M632W8X
OCPTY Electric Water Pump 0392020026
https://www.amazon.com/OCPTY-Electric-0392020026-Mercedes-Benz-Freightliner/dp/B07MDC9MN3
Added:
The Bosch W133 pump body appears to be common for many different vehicles. The only change seems to be the electrical connector. I picked up a brand new Bosch 392 020 024 aka W133-1612030 pump for 30 bucks. For VW I believe. The pump slide connectors will easily adapt to the Sprinter electrical connector. The polarity is clearly marked on the pump.
Hope this does some good. AP/vic
Added:
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On my 2004 it is mounted on the fire wall behind and a bit below the EGR valve. The coolant hose from the EGR is one of the hoses that connects to it. There are two 10 mm head sized nuts which hold the pump bracket to the fire wall. They are a pain to get to, but a socket and extension work. I cut slots in the bracket for the 8 mm studs for re-installation because I knew getting the nuts started would be a PITA. That allowed me to install both nuts partway on and slip the pump into place.