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m38a1 vacuum/pvc lines

Posted: Fri Jan 04, 2019 9:06 pm
by novafied
hi, i'm removing all of the vacuum lines as I have a replacement carb and fuel pump. what is the right way to reconnect the pvc/crankcase breather system? I wanted to install a 12 volt fuel pump but I want to use the vacuum wipers. the replacement fuel pump doesn't have any vacuum assist for the wipers. what is the best way to hook up the wipers? would i need to use the pump spacer with any of the replacement pumps? i'm still looking in the boxes of parts to try to find it. is the spacer easy to get? thanks for your help....bob

Re: m38a1 vacuum/pvc lines

Posted: Fri Jan 04, 2019 9:59 pm
by Joe Gopan
The original M-38 and M-38A1 pumps require the 800361 Spacer, the CJ-3A/CJ-5 Vacuum Boosyer type pumps require the thinner spacer.The MB thru early 50's single action pumps w/o the vacuum booster do not use the spacer.
Buy some M-38A1 TM's and reinstall the original vacuum lines along with a new M-38A1 pump. You can just install breathers at the fuel pump section.

Re: m38a1 vacuum/pvc lines

Posted: Sat Jan 05, 2019 10:37 am
by novafied
thanks ben for the reply. I have most of the tm's for the jeep. I just don't want to all of the vent lines as i'm not doing a so called restoration. i'm keeping the military look on the outside. sort of like a trail ride off road jeep like they were meant to be. I don't have any 24 volt stuff under the hood as I converted all to 12 volt. I just want the basic to make sure the engine is properly vented. I am researching about the cj 3a fuel pump as it has the vacuum hookup for wipers. I hope it comes with proper spacer as no mention of it in ads. looking forward for more advice. thank you...bob

Re: m38a1 vacuum/pvc lines

Posted: Sat Jan 05, 2019 10:42 am
by Joe Gopan
The SPACER for the Vacuum Booster Fuel Pump used on the 4 Cyl CJ is thinner and does not come with the pumps. The CJ Spacer is Willys Part No. 647669. Check with your favorite dealer.

Re: m38a1 vacuum/pvc lines

Posted: Mon Jan 07, 2019 7:03 pm
by novafied
hi ben, thanks again for your reply. I found most of the info I needed on the cj3b.info website. a lot of good info as it uses the same engine. but it's one ugly jeep imo. thanks again....bob

Re: m38a1 vacuum/pvc lines

Posted: Tue Jun 18, 2019 7:11 pm
by TonyRumore
I hope you guys don't mind me jumping in on this thread, but I've got the same issue trying to figure out how to hook up the vacuum wipers. Here's a pic of what I have going on.

There is a vacuum line running from the intake manifold directly below the carb, to the bottom of the fuel pump. The same hard line has a "T" in it and it also runs through what appears to be a check valve and into the side of the block, underneath the exhaust manifold. I don't see any spacer or anywhere to hook the wiper vacuum line. I'm guessing there is some sort of spacer with an attachment port that hooks to the wipers, but I don't know where that spacer is to be installed.

Image

Re: m38a1 vacuum/pvc lines

Posted: Thu Aug 08, 2019 4:41 am
by swampy
the fuel pump is not the correct one