Create an account Home  ·  ·  Forums  ·  ·  Articles  ·  ·  Downloads  ·  ·  Photo Gallery  
Login
Nickname

Password

Don't have an account yet? You can create one here.

Navigation
· Home
· Article Archive
· Article Submit
· Downloads
· FAQ
· Forums
· Members List
· Photo Gallery
· Private Messages
· Web Links
· Your Account

Search Articles



Forums

What's a fair price on M38 Parts?
for you m170 fans
M38 Top Bow pivot point hardware
FS: Fully restored 1955 M38A1
Carb Bracket
M38 Parts for sale
Photo Gallery Request
M38a1 Spark Plug Wires
M38A1 question about serial number
M38A1 smoking

Willys M Jeeps Forums


willysmjeeps.com :: View topic - M38 CDN L-134 willys Fuel Pump
 Forum FAQForum FAQ   SearchSearch   UsergroupsUsergroups   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

M38 CDN L-134 willys Fuel Pump

 
Post new topic   Reply to topic    willysmjeeps.com Forum Index -> Technical Knowledge Base
View previous topic :: View next topic  
Author Message
Lyle
Member


Joined: Nov 01, 2017
Posts: 82
Location: Richmond, BC Canada

PostPosted: Sun Dec 23, 2018 9:40 pm    Post subject: M38 CDN L-134 willys Fuel Pump Reply with quote

I'm installing an Airtex 9562 fuel pump with Vacuum.

Looking for any documentation and/or constructive comments.

It does not have the single port for connecting to venting system from the bell-housing to Transfer-case.

My thoughts are to install a TEE between the outflow of air from Airtex 9562 and the Check Valve connecting to the bell-housing and transfer-case.

That way the Bell-Housing and Tranfser-case will never over pressure since the cracking pressure of the check valve will be 2PSI.
_________________
Lyle
LT-RCEME, Retired
________________
Jeep Rubicon, 2015
M38 CDN, 1952
M416, 1968
Back to top
View user's profile Send private message Send e-mail
wesk
Site Administrator
Site Administrator


Joined: Apr 04, 2005
Posts: 15040
Location: Wisconsin

PostPosted: Sun Dec 23, 2018 10:52 pm    Post subject: Reply with quote

Quote:
I'm installing an Airtex 9562 fuel pump with Vacuum.
Looking for any documentation and/or constructive comments.


Review your fuel pump specs in the TM 9-8012 page 151. Calls for a pump output pressure of 4 to 5 1/4 PSI. Your new Airtex 9562 pump specs:
Quote:
Mechanical Pump 9562
Airtex mechanical fuel pumps are designed to meet or exceed OEM specifications for fit and performance. Precision castings and hardened rockers help ensure a long life. Advanced polymer pump diaphragms help ensure consistent performance in multiple fuel blends.

A new fuel filter is recommended when replacing.

Product Features:

Coverage for classic, performance and non-fuel-injected vehicles.
100% factory tested: Every single pump is 100% tested throughout the entire manufacturing process for worry free, out of the box performance.

WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer, and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov

Gasket Included Y
Inlet Count 1
Inlet Type Threaded
Maximum Pressure Rate (psi) 3.75
Minimum Free Flow Rate (gph) 15 GPH @ 1000 RPM
Minimum Pressure Rate (psi) 2.5
Outlet Count 1
Outlet Size 1/4-18 NPSF
Outlet Type Threaded
Package Contents Pump & Kit
Warranty Limited 1 Year

Warranty Information:
12 Months


Do not compare well in the output pressure. The Airtex 4032 is a little better choice but uses straight tube nipples.

Quote:
My thoughts are to install a TEE between the outflow of air from Airtex 9562 and the Check Valve connecting to the bell-housing and transfer-case.

Waste of time if you do not plan on deep water fording your M38. Not the best way if you do plan on fording. Vacuum side of that port is 10 to 12"
which is equivalent to 5.9 PSI when driving the jeep which is a lot higher than the 2 to 3 PSI used in the crankcase and tranny/transfer fording system. You mention a check valve. Where is this check valve that cracks open at 2 PSI.

There is a very ample supply of the correct rebuilt AC fuel pumps and the correct rebuilding kits to question any need to substitute an unqualified Airtex unit.

More discussion can be found here: http://www.willysmjeeps.com/v2/modules.php?name=Forums&file=viewtopic&t=5974&highlight=
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Ivoryring
Member


Joined: Apr 19, 2016
Posts: 59
Location: Hopkinton, NH

PostPosted: Tue Nov 19, 2019 11:14 am    Post subject: Reply with quote

I hope it's not a problem for me to reply here, but this thread seems to touch on several points for me.

Wes, you mention above that there is an ample supply of correct rebuilt AC fuel pumps, but I'm having a hard time locating one. Nothing to be found on eBay and the web sites I've checked (Midwest Military, debella, Kaiser Willys, army jeep parts) all seem to list "core charge" and/or "core required before we will send" or similar wording. Perhaps I'm overlooking something or looking in the wrong place?

For my purposes, I am planning on deep fording with my M38A1 (if I wasn't, I would just build a CJ5) - but I'm not going for museum quality and don't particularly mind substitution when it will serve functionally.

Aside from needing to make a transition from the straight tube nipples, would the Airtex 4032 work for me? I don't see a spec on the Airtex web site for vacuum... Just your reference above to 10-12" for the 9562 (if I'm reading that right).

I have a pump currently that works to pump fuel - but that doesn't mean it's actually right or outputting the correct fuel pressure or building vacuum to the correct level.
_________________
Tundra (really my name, not my truck)

1952 Willys Overland Model MD (M38A1) #MD25713
2013 Jeep Wrangler Unlimited
Back to top
View user's profile Send private message
wesk
Site Administrator
Site Administrator


Joined: Apr 04, 2005
Posts: 15040
Location: Wisconsin

PostPosted: Tue Nov 19, 2019 11:22 pm    Post subject: Reply with quote

Quote:
Nothing to be found on eBay and the web sites I've checked (Midwest Military, debella, Kaiser Willys, army jeep parts) all seem to list "core charge" and/or "core required before we will send" or similar wording.


I would think based on your remarks, that you did find a few pumps but they were more than you wished to pay and you were not happy with their core requirements. In this hobby one must either be patient and really dig around for used parts and inexpensive rebuilt parts. This means a lot of surfing the net, a lot of surfing your local salvage yards and rebuilders and a lot of car show attendance. The alternative is to dig deep in the wallet and pay!

Quote:
For my purposes, I am planning on deep fording with my M38A1 (if I wasn't, I would just build a CJ5) - but I'm not going for museum quality and don't particularly mind substitution when it will serve functionally.


There is nothing wrong with this approach but when departing from stock on the jeep one must go the extra mile and research compatibility, vs cost vs endurability and performance. The only purpose of the vaccuum system is to support the vacuum operated wipers and the distributor venting system. The required specs for an acceptable amount of suction and an acceptable fuel pressure range are written in the TM's and are easy to find and easy to check with simple test equipment. You do not need a vacuum side to the fuel pump for the fording system to function. When you close the fording valves you do not use vacuum or pressure from the lower side of the dual action fuel fuel/vac pump. The fording valves close the two vents for the engine crankcase and the normal running of the engine creates the increasing internal crankcase pressure to keep the water out. The transfer and tranny are pressurized with this same crankcase pressure but it is delivered thru the center section of the fuel pump and thru the outlet fitting on the center of the fuel pump then to the top vent of the tranny/transfer. The center housing of the dual action fuel pump serves only as a tunnel allowing the crankcase pressure to find it's way to the tranny/transfer.

You'll notice if you start researching the Airtex that no one seems to list vacuum capability of the 4032. Only thing listed is fuel output at 4.0 to 5.5 Lbs at 20 GPH. The requirement for the M38 is 4.0 to 5.25 and the M38A1 4.5 to 5.0.

I see no reason an Airtex pump won't work for you. But if I were headed down your path I would have already converted to electric wipers, a single action high quality fuel pump, a set of disc brakes and a dual master cylinder. I also would have installed a plumbed axle vent system for both axles to stop water entry into them
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Ivoryring
Member


Joined: Apr 19, 2016
Posts: 59
Location: Hopkinton, NH

PostPosted: Wed Nov 20, 2019 6:06 am    Post subject: Reply with quote

wesk wrote:

I would think based on your remarks, that you did find a few pumps but they were more than you wished to pay and you were not happy with their core requirements. In this hobby one must either be patient and really dig around for used parts and inexpensive rebuilt parts. This means a lot of surfing the net, a lot of surfing your local salvage yards and rebuilders and a lot of car show attendance. The alternative is to dig deep in the wallet and pay!


Your insight and experience is definitely appreciated.

I was reading that the comments about 'core required'/'core charge' as directly meaning that - a core exchange is a literal requirement. I am familiar with 'core charge' with things like batteries where it's merely a charge but a return of a bad battery isn't an actual requirement. What I didn't do is reach out to any of those vendors and see if it's a literal requirement. Since I have a currently functioning pump I have the time to keep on hunting around and/or elect to dig into the wallet.

wesk wrote:

There is nothing wrong with this approach but when departing from stock on the jeep one must go the extra mile and research compatibility, vs cost vs endurability and performance. The only purpose of the vaccuum system is to support the vacuum operated wipers and the distributor venting system. The required specs for an acceptable amount of suction and an acceptable fuel pressure range are written in the TM's and are easy to find and easy to check with simple test equipment. You do not need a vacuum side to the fuel pump for the fording system to function. When you close the fording valves you do not use vacuum or pressure from the lower side of the dual action fuel fuel/vac pump. The fording valves close the two vents for the engine crankcase and the normal running of the engine creates the increasing internal crankcase pressure to keep the water out. The transfer and tranny are pressurized with this same crankcase pressure but it is delivered thru the center section of the fuel pump and thru the outlet fitting on the center of the fuel pump then to the top vent of the tranny/transfer. The center housing of the dual action fuel pump serves only as a tunnel allowing the crankcase pressure to find it's way to the tranny/transfer.


This is very interesting and really helps me understand the system better. I've been reading through the TMs and looking at the diagrams, but have had a hard time getting a real grasp of it. Looking at the diagrams I thought that it was the bottom/vacuum half of the fuel pump that was involved with the ventilation lines for the transmission and transfer case. Now that I look again, in TM9-8015-1 pg 151 I see what you mean. Would this missing connection from the center portion of the dual action fuel pump be a portion of why you are saying the Airtex 4032 would be a poor choice?

wesk wrote:

You'll notice if you start researching the Airtex that no one seems to list vacuum capability of the 4032. Only thing listed is fuel output at 4.0 to 5.5 Lbs at 20 GPH. The requirement for the M38 is 4.0 to 5.25 and the M38A1 4.5 to 5.0.

I see no reason an Airtex pump won't work for you. But if I were headed down your path I would have already converted to electric wipers, a single action high quality fuel pump, a set of disc brakes and a dual master cylinder. I also would have installed a plumbed axle vent system for both axles to stop water entry into them


Thank you for your knowledge on this - I'm inclined toward the correct pump rather than the Airtex unit with this info.
_________________
Tundra (really my name, not my truck)

1952 Willys Overland Model MD (M38A1) #MD25713
2013 Jeep Wrangler Unlimited
Back to top
View user's profile Send private message
wesk
Site Administrator
Site Administrator


Joined: Apr 04, 2005
Posts: 15040
Location: Wisconsin

PostPosted: Wed Nov 20, 2019 1:37 pm    Post subject: Reply with quote

Tundra,

Quote:
Since I have a currently functioning pump I have the time to keep on hunting around and/or elect to dig into the wallet.

Some of the vendors only require a core deposit and wait for you to return your core to them after you make the replacement.

Quote:
Would this missing connection from the center portion of the dual action fuel pump be a portion of why you are saying the Airtex 4032 would be a poor choice?


Not necessarily. If you want to ford the jeep then you need to retain the ability to pressurize the tranny/transfer cases. This can be done without a fitting equipped fuel pump. You simply redirect the Fording pressure tube to a different access point to the crankcase. Something as simple as installing a male nipple that matches the pressure tube's end fitting on the valve side cover would work.

A note on the older original M38/M38A1 fuel pumps. You should ascertain they have had the service bulletin TB 9-804-11 complied with .






_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    willysmjeeps.com Forum Index -> Technical Knowledge Base All times are GMT - 6 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

Powered by phpBB © 2001 phpBB Group
Forums ©

 



PHP-Nuke Copyright © 2005 by Francisco Burzi. This is free software, and you may redistribute it under the GPL. PHP-Nuke comes with absolutely no warranty, for details, see the license.