M-37 Radiator and engine block flushing

[Arthur V]

I have had my M-37 for about one year then some and have found the when driving the water temp had gone to the max allowed 200 degree plus. So what I have done is flushed the radiator and still the temp guage had gone to the max., so I removed the thermostat and that took care of the over heating. I have also learned that the engine block has a pet cock as we all know it to be just like the one use to drain the radiator located on the lower left side of the engine.

Well when I went to open it I'm not getting any water from that location so one question is why was my engine temp maxed out with a new thermostat rated at 1800 and why is it I'm not getting any water from the pet cock on the lower left side of the engine..

Sure could use some help here..

Thanks
Arthur

[Gordon Maney]

I have had my M-37 for about one year then some and have found the when driving the water temp had gone to the max allowed 200 degree plus.

So what I have done is flushed the radiator and still the temp gauge had gone to the max., so I removed the thermostat and that took care of the over heating.

I have also learned that the engine block has a pet cock as we all know it to be just like the one use to drain the radiator located on the lower left side of the engine.

Well when I went to open it I'm not getting any water from that location so one question is why was my engine temp maxed out with a new thermostat rated at 180 and why is it I'm not getting any water from the pet cock on the lower left side of the engine..

Sure could use some help here..

Thanks
Arthur

Arthur, several thoughts. You say removing the thermostat took care of the overheating. What is your gauge reading at that point?

Toward the end you mention temperature being high with a new thermostat. Is that the one you took out, or did you put in a new one after taking the first one out?

If the petcock truly is tapped into the water jacket of the block, then a reason why water would not come out is that the hole is blocked with rust and sediment. Try poking a scratch awl or some other pointed tool into the hole. If it is cooling jacket you will get water by poking a hole in the crud.

[Arthur V]

M-37 Radiator and engine block flushing

Gordon, First of thanks for your help here. Yes I have replaced the thermostat with a new one and it will still max out the temp as indicated at 200 degrees, now the temp with out the thermostast is holding at 125 degrees with no thermostat the guage is below the mid point.

I have not poked a hole through the petcock in the side of the engine bolck flush port. I will next time I'm able to as I was kinda sleptical of doing some damage. Now by removing the petcock is there anything else that will keep the water from coming out other then crud as you have mentioned? How far should I poke this hole so to release the water. I have to put antifreeze to keep it from rusting on me is that correct..

Thanks Gordon

[Gordon Maney]

Gordon, First of thanks for your help here. Yes I have replaced the thermostat with a new one and it will still max out the temp as indicated at 200 degrees,

OK, gotcha.

now the temp with out the thermostat is holding at 125 degrees with no thermostat the gauge is below the mid point.

A useful bit of diagnostic information. Long term we don't want to run without a thermostat, but it is fine for now.

I have not poked a hole through the petcock in the side of the engine block flush port. I will next time I'm able to as I was kinda skeptical of doing some damage.

You can't hurt anything, so don't worry about that. Just push with your hand. Don't drive a sharp punch in with a two pound hammer, however. :-)

Now by removing the petcock is there anything else that will keep the water from coming out other than crud as you have mentioned?

No

How far should I poke this hole so to release the water. I have to put antifreeze to keep it from rusting on me is that correct.

As far as you have to. It won't be far, perhaps as little as 1/16 inch, maybe as much as 1/2 inch. You don't say where you live, to help me know if it will freeze there. If you are not at risk for freezing, then you can leave plain water in it during your diagnostic efforts.

[Arthur V]

Ok I will be careful not to use a hammer.... :-) Now to answer your question on antifreeze I'm in LA Lower Alabama near the Florida line about 30 miles give or take a mile. Once I get he water flow from the engine block I will flush the sys again and install the new theromostat and see if the temp will hold at a normal temp.

My M-37 is housed all the time winter and summer etc at the airport hanger.. I like my truck but this guy I bought it from used it for show btu I want more then show it off.

I use to drive one of these in Germany and Viet-nam and if I had the tools and the shop I would take this thing apart but time, job etc will not allow me to do it..

Q. So what would be the normal temp on one of these engines?

Thanks

[Gordon Maney]

Ok I will be careful not to use a hammer.... :-) Now to answer your question on antifreeze I'm in LA Lower Alabama near the Florida line about 30 miles give or take a mile. Once I get he water flow from the engine block I will flush the sys again and install the new theromostat and see if the temp will hold at a normal temp.

My M-37 is housed all the time winter and summer etc at the airport hanger.. I like my truck but this guy I bought it from used it for show btu I want more then show it off.

I use to drive one of these in Germany and Viet-nam and if I had the tools and the shop I would take this thing apart but time, job etc will not allow me to do it..

Q. So what would be the normal temp on one of these engines?

Thanks

I suspect you won't be freezing there.

As for temperature, around 180 is fine. In cold winter it might only reach 160, but you don't have that.

Try a good flush first. If that does not work you may have to remove the radiator and have it cleaned.

[Paul Cook]

Don't forget...

the WATER DISTRIBUTION TUBE. This subject has been well covered in the Power Wagon Advertiser forum and other Power Wagon forums. Still, I would be remiss if I failed to mention block length.

Since you have owned your M37 for a year, I'm sure you have an operators manual TM 9-8030 which has detailed instructions for flushing block and radiator.

If you do not have the ORD 9 SNL G-741 parts list,yet, here is the information on the drain cocks.

COCK, Drain, automotive, tee hdl, br, 1/4 male pipe end, Stock No. H006-0585891, MFR'S Part No. WH-211110 / CC-863015 (Fig 81, & Fig 152, TM 9-8030)

One on block (Fig 81) and one on radiator (Fig 152). If original or correct replacement, you cannot push anything through to clean. You will have to remove them and clean with a brush. If you can afford it, you are better off to buy replacements since the tee handle is usually abused by attempts to open/close the drain cock with various tools instead of correctly by hand.

I hope this helps.

[Gordon Maney]

the WATER DISTRIBUTION TUBE. This subject has been well covered in the Power Wagon Advertiser forum and other Power Wagon forums. Still, I would be remiss if I failed to mention block length.

Since you have owned your M37 for a year, I'm sure you have an operators manual TM 9-8030 which has detailed instructions for flushing block and radiator.

If you do not have the ORD 9 SNL G-741 parts list,yet, here is the information on the drain cocks.

COCK, Drain, automotive, tee hdl, br, 1/4 male pipe end, Stock No. H006-0585891, MFR'S Part No. WH-211110 / CC-863015 (Fig 81, & Fig 152, TM 9-8030)

One on block (Fig 81) and one on radiator (Fig 152). If original or correct replacement, you cannot push anything through to clean. You will have to remove them and clean with a brush. If you can afford it, you are better off to buy replacements since the tee handle is usually abused by attempts to open/close the drain cock with various tools instead of correctly by hand.

I hope this helps.

Good job on the distribution tube.

Also, I failed to mention he would have to remove the petcock before probing. I was thinking it, but not writing it.

Us younger guys always appreciate guidance offered by you older guys....

:-)

[Arthur V]

Ok I got all the inforamtion I think I need as I had no idea I had to remove the pipe that the petcock is screwed to , Wow I'm thinking it's a tight spot as you both know and one of you mentioned that it has been abused you are so right.

Now if I go putting presure on the pipe fitting that the petcock is screwed to and I happen to brake it for some reason since that pipe has been there for ages now what. I can about to imagine what's next but I will try it anyway.

It's good to learn from those that have the knowledge rather then me just doing something stupid. The radiator is in good shape since I have flushed the upper water jacket since I have had it minus the thermostat. I plan to install a new one once I have drained the lower water jacket as I have learned the upper water jacket was full of slugh etc.

It's looking good so far there is finally clear water coiming through last since so I know that the radiator and the water pump are in working order since I have drove it last which was this past few days. Thanks Paul and Gordon for your help as I will be coming back on the forum when I get the task done. If I need parts for my M-37 who do you recommend I get the parts from?

Art.

[Gordon Maney]

While you are thinking about all this, get penetrating oil working on the threads of the fittings. I don't know what you have for a fitting assembly. A petcock screwed into an iron fitting that screws into the block?

Don't worry about ruining the valve, if that is the case. It is unlikely you will have difficulty getting the iron fitting out of the block. Remember the penetrating oil. Let it soak for days, if you are worried. Can you get at it better from below?

Clear water coming out does not necessarily mean your radiator is clean. You can have a layer of material that is firmly attached to the inside of core tubes that will let clear water go right past it.

[Arthur V]

You are correct the petcock screws on the fitting then the fitting screws in on the pipe then to the block.

Yes I have thought about the penatrating oil and if I have to get the radiator fushed then I will do it since I will be waiting to get this petcock issue taken care of. Some one sent me a web site for the parts as I have not checked it out yet.

Since I have you on the forum and I hope you don't me asking all these questions. Is there a way I can make my M-37 run faster then the top speed of 45 MPH? My friend has a WC and he runs away from me and has to wait on me, just asking?

Again thank Mr Gordon and I see you own one to. I will have to post mine on the forum too..

[Gordon Maney]

You are correct the petcock screws on the fitting then the fitting screws in on the pipe then to the block.

Yes I have thought about the penetrating oil and if I have to get the radiator flushed then I will do it since I will be waiting to get this petcock issue taken care of. Some one sent me a web site for the parts as I have not checked it out yet.

Since I have you on the forum and I hope you don't me asking all these questions. Is there a way I can make my M-37 run faster then the top speed of 45 MPH? My friend has a WC and he runs away from me and has to wait on me, just asking?

Again thank Mr Gordon and I see you own one to. I will have to post mine on the forum too..

Since I have you on the forum and I hope you don't me asking all these questions.

That's why the forum is here. This is what we do. :-)

I am straining to know the magnitude of runs away. His may simply be in a different state of tune. You could have a carburetor governor issue. You could have really low compression. It is hard to know the differences between your truck and his.

[Gordon Maney]

See Vintage Power Wagons for parts, and also appropriate manuals you would find very useful.

[Arthur V]

Well I thought WC and M-37 have the same engine. I will have to ask my friend that owns one. I thought the governor were installed to keep the truck from running away compared to the gear system these trucks were manufactured to run mainly off road...

Am I correct...?

[Gordon Maney]

The idea behind the governor was to limit maximum road/engine speed.