Has anyone had a CM30 fail on them?
Thread Starter
MBWorld Fanatic!
Joined: Jul 2003
Posts: 2,123
Likes: 3
From: Chicago, IL
Real Cars
Has anyone had a CM30 fail on them?
How long did it last you? How did you figure out it failed?
I think mine has failed on my 55, but it's difficult to know for sure until I replace it (Thursday).
-m
I think mine has failed on my 55, but it's difficult to know for sure until I replace it (Thursday).
-m
Thread Starter
MBWorld Fanatic!
Joined: Jul 2003
Posts: 2,123
Likes: 3
From: Chicago, IL
Real Cars
After reading everyone's responses on here, and in my datalogging thread (https://mbworld.org/forums/w211-amg/...rs-thread.html), I think it's time to call it quits with the CM30. I'm ordering up a Meziere pump and going to try that.
It looks like the days of recommending the CM30 to people are numbered...
Thanks to everyone for the advice.
-m
It looks like the days of recommending the CM30 to people are numbered...
Thanks to everyone for the advice.
-m
Thread Starter
MBWorld Fanatic!
Joined: Jul 2003
Posts: 2,123
Likes: 3
From: Chicago, IL
Real Cars
-m
MBWorld Fanatic!
Joined: Nov 2006
Posts: 9,137
Likes: 4
From: California, USA
E63 P30, CL500 Sport
I personally know of at least 4 guys local to me that have been running CM30 for the past couple of years with no problems. My understanding was that they do not have a very high failure rate 
Most of my friends do not data log regularly though, but they do log once in a while (mostly at the track). One of them runs the car very hard almost all the time.... I'll ask him if he has noticed any problems with his CM30.
Most of my friends do not data log regularly though, but they do log once in a while (mostly at the track). One of them runs the car very hard almost all the time.... I'll ask him if he has noticed any problems with his CM30.
Trending Topics
Out Of Control!!
Joined: Sep 2004
Posts: 13,394
Likes: 6
From: San Diego
2015 S212
Any pump can fail but the CM series are pretty stout. I'm not a personal fan and prefer a pump made to handle the fluids that we run (i.e. an automotive cooling pump like the Davies). I haven't tried the one shardul is touting but he is a straight up dude so that may also be an option.
The CM30 is honestly only good because minimal mods are needed to mount it. the newer OEM pumps are just as good IMO.
The CM30 is honestly only good because minimal mods are needed to mount it. the newer OEM pumps are just as good IMO.
MB World Stories
The Best of Mercedes & AMG
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
MBWorld Fanatic!
Joined: Apr 2008
Posts: 1,762
Likes: 1
From: Queens, NY
04 w211 E55
I have the Cm30 pump over 1 year and actually never had a problem with my s.c turning off.
Unfortunately I do have a problem. My Cm30 is not sealed sumwhere cauz its now leaking and I have my coolant leaking slowly. I found out first time I installed but I tried to seal it but it now started leaking again.
I ordered a spare Cm30 pump just incase I ever run into problems and its brand new in the box. I'm going to install the new 1 when i get a chance.
Unfortunately I do have a problem. My Cm30 is not sealed sumwhere cauz its now leaking and I have my coolant leaking slowly. I found out first time I installed but I tried to seal it but it now started leaking again.
I ordered a spare Cm30 pump just incase I ever run into problems and its brand new in the box. I'm going to install the new 1 when i get a chance.
Out Of Control!!
Joined: Feb 2003
Posts: 13,489
Likes: 96
haters crazy
My C090 failed twice. They start leaking internally and get corroded and give out. At least thats what happened to mine. I like to take stuff apart after they fail to find out why or at least try.
Meziere makes great durable pumps. Lots of race cars use them. Lots of cobras use them too.
Meziere makes great durable pumps. Lots of race cars use them. Lots of cobras use them too.
MBWorld Fanatic!
Joined: Sep 2008
Posts: 3,152
Likes: 0
From: murfreesboro,tn
2003 porsche 996 turbo
i have the cm30 in mine without issues for over a yr now.
something to consider with the meziere or any other high volume pump is the flow rate. dont get one so big it overloads the i/c and causes a possible leak. just a thought.
something to consider with the meziere or any other high volume pump is the flow rate. dont get one so big it overloads the i/c and causes a possible leak. just a thought.
MBWorld Fanatic!
Joined: Aug 2005
Posts: 3,466
Likes: 10
From: Southern Cali (Ontario)
I have cm30 on both of my cars.
1 pump has about 2+ years (c32)
and the other is under 1 year. (E55)
Next I'm going to upgrade to the CM90 with 20mm or 3/4" connections... not as free flowing as the 1" connector, but faster than Cm30.
I will look into the Mezerie pump as well.. but probably will need to see a write up to mount it correctly.
1 pump has about 2+ years (c32)
and the other is under 1 year. (E55)
Next I'm going to upgrade to the CM90 with 20mm or 3/4" connections... not as free flowing as the 1" connector, but faster than Cm30.
I will look into the Mezerie pump as well.. but probably will need to see a write up to mount it correctly.
Thread Starter
MBWorld Fanatic!
Joined: Jul 2003
Posts: 2,123
Likes: 3
From: Chicago, IL
Real Cars
If anyone is interested in ordering the Meziere, you need three things - the pump itself and the two fittings. These are the part numbers. They are available from Jegs/Summit/etc.
WP136S PUMP (x1)
WP12034B -12 AN to 3/4" FITTINGS (x2)
WP136S PUMP (x1)
WP12034B -12 AN to 3/4" FITTINGS (x2)
PLATINUM SPONSOR
Joined: Jun 2008
Posts: 3,834
Likes: 65
From: Texas
2003 CL55
My stock pump went out, as I raced a vette two years ago. Won the first race but got beat the second..lol I knew something was wrong! Bought a data logger and Iat`s were hitting 200 plus.. Read the forum and got suckered into the Cm30
Data logged and seemed good. Drove a few weeks and car felt week again. Put data log on and bad Cm30.. Of course MFG blammed my install , blah blah blah.. Bought another one and it showed to be running cool and fine.. Went to a dyno ,, made two pulls and heater hoses blew off the car on the dyno!!! Again, Cm30 was out and caused me a ton of grief! Both pumps lasted about 150 miles.. Most people may never know, unless they data log, gets hot outside or they are real in-tune with their car.. The CL, S and SL class seem to eat them faster. They also have more fins to push water through on their stock H/E..
I ran the stock HD Bosch pump and had zero issues , until finding the super mega Meziere pump! It runs full time.. Pretty wild seeing IAT`s 48 deg. on a 40 degree day..
That is a leat 50 deg. lower than people running ECU controlled stock or CM30 pumps..Here is the Meziere next to stock HD Bosch pump.. The Cm30 is much smaller than both, if size matters to you..
__________________
E63 Biturbo, UPD Cold Air induction kit, UPD performance crank pulley and UPD adjustable rear suspension with ride height adjustment.
CL55 UPD Cold Air Boost kit, UPD 3000 stall converter, UPD 77mm SC clutched pulley and beltwrap kit, Custom long tubes, UPD crank pulley , UPD suspension kit, UPD SC pulley, Aux. HE, Trunk tank w/rule 2000 pump, Mezeire pump, UPD 5pc idler set, Aluminum rotor hats.
www.ultimatepd.com
instagram @ultimate_pd
facebook.com/ultimatepd
E63 Biturbo, UPD Cold Air induction kit, UPD performance crank pulley and UPD adjustable rear suspension with ride height adjustment.
CL55 UPD Cold Air Boost kit, UPD 3000 stall converter, UPD 77mm SC clutched pulley and beltwrap kit, Custom long tubes, UPD crank pulley , UPD suspension kit, UPD SC pulley, Aux. HE, Trunk tank w/rule 2000 pump, Mezeire pump, UPD 5pc idler set, Aluminum rotor hats.
www.ultimatepd.com
instagram @ultimate_pd
facebook.com/ultimatepd
Last edited by Exotic-metal55; Feb 10, 2010 at 03:08 PM.
Everyone says they have a big one.. 
Out Of Control!!
Joined: Feb 2003
Posts: 13,489
Likes: 96
haters crazy
CM90: 244 mm long x 120 mm wide x 150 mm high
Meziere WP136S: 190.5mm tall x 88.9mm wide x 88.9 long
Ahem, mines bigger
The Meziere is cheaper, flows more, and fits into a smaller space. The Johnson pumps have inlet/outlet oriented the same as stock (90 degrees) but the Meziere has them 180 degrees apart. FYI, Kleemann uses Johnson C090 pumps with their sc kits.
FYI, too much flow can be bad and can cause the coolant to foam
Last edited by blackbenzz; Feb 10, 2010 at 03:35 PM.
