Cold start valve replacement 1970 280 sl

[Mgordon]

I am looking for a cold start valve!!
Part # I believe is 0000712537.
Am finding prices all over the map.
Can it be rebuilt and who will do it for me.
Fuel leaking heavily out the top of valve.
Hope one of you fine gentlemen will help me!

Michael

[FresnoBob]

There are several O-rings and gaskets on these.  Did you try replacing them if the unit is working correctly?  A test light on the brown and black wires will show if the 1 second relay and/or Thermo Time Switch are giving it the required 12 volts.  You should also hear a distinctive "click" when the device actuates. 

[Lorsar]

Join as a full member to get access to the tech manual.  As Bob said,  more than likely you just need to take it apart, clean it and replace the o rings

https://www.sl113.org/wiki/Engine/ColdStartValve

[rwmastel]

Michael,

Welcome to the group!  I see you just recently joined.  My best recommendation is to use the Search feature.  I would say that 99% of the problems you face and need help with, someone else has already posted the same problem or asked the same question.  I recall reading a thread recently about this same part leaking.  And if you join as a Full Member, Lorsar is right about using the Technical Manual to learn about systems and components.  Best of luck getting this worked out quickly!

[mnahon]

Michael,

From what I can see in your picture, your CSV is the later small diameter type. I imagine your Pagoda is a 70 or 71. So the part number you have is not correct; that part number is for the earlier large diameter type.

If your CSV is leaking from the top of the solenoid (around the black plastic near where the wire attaches), then the solenoid probably needs to be replaced. The solenoid is hard to find. Also note that the solenoid for the later CSV is different from the one on the earlier CSV.

Meyer

[Mgordon]

I just became a full member 👍👍🕺🏽

[Mgordon]

Meyer,
In case I can not rebuild the CSV. Do you know what the correct part number is ?
My car is 1970 280 SL.
MICHAEL

[stickandrudderman]

I'm curious as to why there are two wires attached to your solenoid when there should only be one.

[Mgordon]

That’s a great question!
My 97 year old dads mechanic who has since died, installed this.
We are trying to get to the bottom of that.
More to come on that.

[Paul & Dolly]

It is possible that someone has wired an additional power supply to manually activate the CSV.
Have you checked when it is getting power during a starting attempt?

Paul

[mnahon]

Hi Michael,

Can you confirm you have a 70 or 71 280SL? Because those are the ones that used the smaller diameter CSV.  I can't be certain because of the angle of your picture.

Assuming that it is a small-diameter CSV, the Mercedes P/N is 0000713037

Another way to identify your present one is to look at the part number on the solenoid, which should be fairly easy to read. If it ends in 001, then it's the earlier large diameter CSV. If it ends in 004, then you have the later small diameter CSV.

Regarding the leak: if the solenoid is leaking from its base (where it screws into the CSV), you may be able to fix it by changing the o-ring. If it's leaking from the top (where the black plastic cap is), then you likely need a new solenoid.

Meyer

[Mgordon]

Thanks Meyer.
I will contact you tomorrow and let you know what the part number is. 👍

[mnahon]

Hi Michael,

If the second wire on the CSV is from a manual switch in the cockpit, the car has been modified for manual operation of the CSV, likely because the original automatic system was not working properly.

A lot has been written on this. There are some who prefer this manual actuation because it gives them more direct control of the operation of the CSV. And there are those who prefer to get the original system working for the sake of originality.

In the original system, the CSV is energized by the cold start relay. While the relay itself is energized when the starter motor is energized, it is only sometimes grounded (in order to send voltage to the CSV, the relay needs to also be grounded). Grounding of the relay is done by the thermo time switch. A description of the operation of the original system is given in the starting aids tour:
https://www.sl113.org/wiki/Restricted/Engine-starting-aid-tour

All told, diagnosing this system is not simple, but there have been many threads written on this, so if you persevere, you will eventually eventually get it working. But when you do, you may wonder whether it was worth all the work. i.e. manual actuation is much simpler and it gets the job done.

Here are some threads on the topic (this is just a small sample):
https://www.sl113.org/forums/index.php?topic=825
https://www.sl113.org/forums/index.php?topic=35052
https://www.sl113.org/forums/index.php?topic=30120
Manual operation:
https://www.sl113.org/forums/index.php?topic=31189


Meyer