M170 fuel system questions

Claudio · Post by **Claudio** » Wed Sep 22, 2010 8:32 pm

Hi, I recently bought a fuel pump on Ebay for my M170.
Diaphragms replaced, all moving parts checked, seems to be everything OK. Now I am struggling to install it, since it is missing the spacer and also the long bolts, as foreseen for this installation. So questions:
(1) - Do you guys have the correct dimensions of these bolts and the lenght of the threaded end?
(2) - I also need a picture / dimensions of the fuel pump spacer ?
(3) - another fuel system question: my fuel tank had its fuel filter removed, so do you have any picture of it to help me finding a similar around in the market?
Thanks, best!
Claudio
Florianopolis, Brazil

Post by **wesk** » Wed Sep 22, 2010 9:57 pm

Spacer and bolts should be available from Midwest Military or AJP.

MWM page 6 spacer = $12
http://www.midwestmil.com/m38a1p6.html

MWM Page 7 Fuel Pump Bolt, Special - 7375385 $7.00/each
http://www.midwestmil.com/m38a1p7.html

The spacer is between 1/2" and 9/16" thick.

The original 7375385 (WO# 800741) bolt was 5/16-18NC-3x2 which would have an overall length of 2"

The Willys amended bolt spec for 7375385 (WO# 800741) introduced during M38A1 production was 5/16-18NC-3x5 1/8".

The short bolt for the early M38A1 became 122058 5/16-18NC-3x1 7/8"
but was later amended to a 8332521 (WO# 809689) 5/16-18NC-3x3 1/8"

The final choice for the two special bolts would be 7375385 5 1/8" overall length forward and 8332521 3 1/8" overall length aft.

So Midwest Mil can supply the long bolt and the spacer. Zane is advertising the short special bolt on the G503 board for $10 http://www.g503.com/forums/viewtopic.php?f=12&t=171008

You won't have much luck locating a filter that will fit in place of the original in tank filter. They are all a little different from each other due to different shape fuel tanks. Midwest has them in stock:

The long tube is M38A1 and the short tube is M38.

idiocrates · Post by **idiocrates** » Thu Sep 23, 2010 12:08 pm

I think this a picture of the spacer.......
[url=http://www.flickr.com/photos/22032 ... .jpg[/img]
P1010007 by idiocrates, on Flickr
[/url]
at least its what I bought for the fuel pump on my F-134 which had no spacer only an external fuel pressure regulator.

Claudio · Post by **Claudio** » Thu Sep 23, 2010 6:04 pm

Thank you Wes, thanks Jim,

Even with the thicker 9/16" spacer, I'm still having problems to install the fuel pump, as its large diameter housing touches the engine front mounting plate.
My TM-9-8014 Manual, page 155, shows a picture of the fuel pump assembly and looks clear that the upper fuel housing of the pump is spaced way higher from the engine mounting plate. Mine touches the mounting plate. I can't find the reason why.
I have currently in hands a civilian pump that has a smaller housing diameter, doesn't need any spacer, neither long bolts, bla bla bla...but still not original...and I also doubt if these civvy pumps would give enough vaccum flow to ensure ventilation of the 24V coil. What about that?

Could later model Hurricane engines be equipped with a different and larger engine mounting plate? Please give me a help!!!

Thanks again!
Claudio - Flrianopolis, Brazil

Post by **wesk** » Thu Sep 23, 2010 7:29 pm

Sounds like you have the wrong front engine mounting plate. The correct plate is pictured below.

nepperjepper · Post by **nepperjepper** » Thu Sep 23, 2010 7:50 pm

I had the wrong engine mounting plate in mine also. Rather than change it I did some work with a cut off wheel and made it work…Jeff

Claudio · Post by **Claudio** » Thu Sep 23, 2010 10:20 pm

Oh well...it is almost 1:00 AM in Brazil...seems that the first spring night will still be cold and rainy...not good news though...besides that, forecast indicates rainy weather over the weekend...buuuuut still very good "encouraging" news from you guys, thank you!!!
Since I am not going to replace the engine of the jeep exclusively to fit the correct fuel pump, neither look for an engine with other mounting pate, it remains only the alternative to proceed small changes on the engine mounting plate to allow installation of the fuel pump, the same way Jeff did on his jeep. I will make photos to have all this recorded and let others know about these issues.
After all these discussions about the ventilation/vaccum system of my of M170 (and othe M's from the same vintage), I am now seriously concerned to find out the original specifications and configuration of these Mseries vehicles' engines that have been supplied to Brazil during early 60's.
Thanks again, all best!
Claudio

Claudio · Post by **Claudio** » Mon Sep 27, 2010 5:36 am

Hi, the installation of the pump worked fine, the small port for fitting the lower fuel pump bowl was actually there, so I only had to remove about 2mm of the engine mount plate to allow a comfortable installation of the pump. My best thanks Wes!
Now it remains another question: the late style air filter (with flat head) outlet gives no allignment with the YS carburator, still considering that the crossover tube has to be installed. Can you give me a hint?
Regards
Claudio - Florianopolis, Brazil

Post by **wesk** » Mon Sep 27, 2010 8:22 am

The late 62 and newer jeeps with the flat style air cleaner should look like this:

Post by **wesk** » Mon Sep 27, 2010 8:33 am

Claudio,

You're air cleaner is incorrect. It is for the M151.

Claudio · Post by **Claudio** » Mon Sep 27, 2010 9:32 am

I see no big difference of the shape of the flat head of the air filters (MUTT x M170). Mine had its final end of the air outlet neck replaced by a larger diameter tube (welded), while the original seems to look thinner at the final end. The MUTT air filter has 2 breathers (one at the filter itself and the other one on the "mushroom"pre-filter). Mine has none of these. Still confused...

Thanks Wes!
Best!