Ambac M-50 Rebuild w/ pics (MEP-003A)

[jmathis0809]

Quick questions. I have a Mep-002a generator, and I am having problems out of the fuel pumps. Do you have or know a video on breaking down one? And where would a good location to buy parts from it be?

 

[Guyfang]

What is the problem?

 

[jmathis0809]

What is the problem?

They wont pump enough fuel through to operate the machine. I bypassed it and used a standard 12 volt carter pump and it ran fine. I took the pumps off, and the filters where full of gunk. I haven't tried to run it outside of the machine yet, because I know I have to replace those filters and have not found a place to get them from yet. I was just hoping to see a video to a quick clean on one to help me. I am a rookie to this kind of work, lol.

 

[Guyfang]

They are easy to clean. Just look at the diagram i sent and take them apart. Soak the filters and blow them out. From inside the filter, to outside. Also test them one at a time to make sure they both run.

 

[Ray70]

I wouldn't worry about buying parts for the original pump. If you disassemble it and clean everything including the 2 check balls, plunger and strainer, etc. and it still doesn't work there is nothing else you can "replace". At that point your best bet is just purchase either an Airtex 24V pump ( such as an E8135 ) or an off brand 24V pump ( both are less than $50 ) compared to well over $200 for most places selling the original Facet pumps.
Also, clip off the EMI suppressor. If the pump doesn't run at all, the suppressor could be the problem.
If it runs but doesn't pump fuel, the check balls are most likely stuck and need cleaning.

 

[Ray70]

Ah, you guys were typing faster than me! You got 2 replies in before I could type 1.
Sounds like your check balls are not working correctly as well as clogged strainer.
Clean everything up and reassemble and test, you should be fine.
I have never seen a video, but they are so simple to take apart I never looked.
Twist off the base with a wrench, the little wire clip in the bottom of the tube holds everything together.
Remove that wire clip and everything will come out. Just keep it in order and keep track of the check ball orientation.

 

[jmenende]

I usually never have to take them off. Just clean the filter and magnetic lid with carb cleaner, then spray inside the pump till the gunk is out and most important part is to finger up and down the check ball with your pinkie. They are usually just a bit stuck. Make sure you bleed the line after that since gunk might make it to the IP.

 

[Chainbreaker]

...I know I have to replace those filters and have not found a place to get them from yet.

You can buy the Facet pump strainers w/gasket here for $7.95 ea or currently on eBay for $16 ea, + shipping.

Regardless, it's still good to have a set on hand even if you can clean the old ones just in case you were to get a tear/puncture in the filter membrane.

 

[jmathis0809]

What is the problem?

I ended up cleaning them out really good. Only problem came when I bench tested them afterwards, they wouldn't run at all. May not have been running before I cleaned them. I took off the the pump for the alternate fuel, cleaned it (didn't really need it. Looked like it had never been used before, but went ahead and cleaned it while I had it off). Took off the solenoid and bench test that one and it worked fine. Do you think it will be a problem to run it with that one fuel pump or should I try to get another one? Thanks for the advice.

 

[Ray70]

It sounds like you plan to take the Aux. fuel pump and remove the solenoid and use it in place of the primary pumps?
If so, that will be fine. The 2 primaries are for redundancy, you only need 1 to make the machine run.
I often tell people to unplug one of their primary pumps to "save it for when needed " that way it isn't running all the time.
If 1 dies, just plug in your backup.

 

[Guyfang]

Did you follow Ray's suggestion to:

Also, clip off the EMI suppressor. If the pump doesn't run at all, the suppressor could be the problem.

If not,m clip the EMI off, and then hook them to 24 VDC, to see if thats the problem.

 

[jmathis0809]

Did you follow Ray's suggestion to:

Also, clip off the EMI suppressor. If the pump doesn't run at all, the suppressor could be the problem.

If not,m clip the EMI off, and then hook them to 24 VDC, to see if thats the problem.

I did do that and they still didn't work. I actually did that before he even said anything even though I didn't know what it was. Was just trying to figure out an option when it wasn't working.

 

[Guyfang]

Rare that they BOTH go bad. Do they even vibrate a tad, when you first energize them? And you had the pump body grounded tightly when you applied 24 VDC?

 

[jmathis0809]

Rare that they BOTH go bad. Do they even vibrate a tad, when you first energize them? And you had the pump body grounded tightly when you applied 24 VDC?

It didn't vibrate or make any sounds at all. The generators have been sitting about 10 years before my boss had bought them. Still had old fuel in it.

He actually has three of them. 2 mep

 

[jmathis0809]

It didn't vibrate or make any sounds at all. The generators have been sitting about 10 years before my boss had bought them. Still had old fuel in it.

He actually has three of them. 2 mep

2 MEP002a and 003a. Ones having the fuel pump problems. One bad starter. The 003a we still don't know what's wrong with it.

 

[Guyfang]

Then start a thread on it. Tell us whats up.

 

[Chainbreaker]

2 MEP002a and 003a. Ones having the fuel pump problems. One bad starter. The 003a we still don't know what's wrong with it.

If they have had fuel sitting in them for 10 years it could be the internals of the fuel pumps are completely gummed up or rusted if there was any water in fuel. Many have had good luck disassembling the pumps as they have a retaining clip inside that can be removed to disassemble the pump internals and clean them up.

 

[Ray70]

In addition, if they have been sitting for 10+ years with fuel in them, be very careful not to trash your injection pump. If the IP is gummed up and you crank the motor over you will damage an Ambac M-50 pump and you will turn a Bosch PSU pump into scrap metal.
There is a procedure to check and free up the IP listed up top in the stickies I believe, but you have to do it before cranking it over at all.

 

[Kkkpack]

Does anyone recall if the 509-0094 oring from the pump to the block is round or kind of flat?
The old O’ring is still pliable but I hate to put it back on and have to take it off again.
I believe it’s flattened from being on there so long, a new one is about 30 plus shipping.
I’d like to match something from local so we would have an alternative number.

 

[Guyfang]

This was all the tech data I could find.

	CROSS-SECTIONAL HEIGHT	0 1/8 INCHES NOMINAL
	MATERIAL	RUBBER