Post by Scoutpilot on Dec 29, 2014 13:02:32 GMT -5
From the outside, most of the pumps for the L134 look alike. At first glance, to the untrained eye. The top two photos show original AC 572 pumps. The one on the left, in both photos, is the military issue with the priming handle. Stamped into the mounting flange should be the number "9716". On the right is the civilian version. Stamped into the mounting flange should be the number "1523089". Very Early models had few, if any other markings. Later versions had the symbols "AC" and the model number "1523089" cast into the lower flange of the body. Very late models carry the part number "40098" cast into the flange. Note the full brass mesh screen and the square detent between the base of the top and in the lever body. Note as well, the bail nut has ten points.
In the bottom photo you will observe two later model pumps for the L134. The one on the left is a Carter M2195, single action and the one on the right is an Airtex Clone.
Last Edit: Apr 7, 2015 4:24:48 GMT -5 by Scoutpilot
There has always been some concern about the need for a spacer between the fuel pump and the block. The purpose of the spacer is to move the contact area between the pump arm and the cam outward, thereby shortening the stroke of the pump in order to lower the fuel pressure output. The MB/GPW and the CJ2A, up until the '48 model year, utilize a single action pump which does not require the use of a spacer. At first, only the AC572 was used. Carter eventually introduced their version in the M2195.
With advent of the CJ3A, the Navy and USMC's CJV35/U and the Army's M38, a dual action (fuel and vacuum) pump was introduced. The AC4032 utilized a spacer between the fuel pump and the engine block. Over the years the spacer is often removed, and lost, for various reasons. The CJ-2A style fuel pump is often retrofitted to these vehicles due to its lower cost. This is a fuel pump only, without the vacuum booster section. It does not require a spacer for proper operation. Lack of a spacer on the original CJ-3A, CJV-35/U and M38 fuel pumps can cause excessive fuel pressure. Fuel pressure can be lowered slightly by adding extra gaskets between the fuel pump and engine block.
Last Edit: Apr 5, 2015 12:57:05 GMT -5 by Scoutpilot
The AC 572 (and clones)should be putting out 15 gph at 2.5 - 5 psig. You can test your single action fuel pump.
On the Bench:
Attach a vacuum gauge/fuel pressure tester to the outlet. Pump the lever 4 - 5 times. Pressure should not bleed off quickly.
Attach a vacuum gauge/fuel pressure tester to the inlet. Pump the lever 4 - 5 times. Vacuum should not bleed off quickly.
In the Jeep:
Disconnect the carb end of the fuel line. Place that end in a large glass jar. With the fire extinguisher handy, hold the tube in the jar and have someone crank the motor for 10-15 seconds. Measure the fuel in the jar and it should be about 1/2 pint.
Install an in-line fuel pressure gauge between the pump and carb. Keep it simple. Observe the pressure while running. It can be as low as 2.5 psig or as high as 5 psig.
When running the pump under normal circumstances, as long as the center pylon is covered with fuel, the engine should perform normally. The Bowl is an air dome that maintains back pressure in the pump.
Last Edit: Jan 19, 2015 6:12:01 GMT -5 by Scoutpilot
Post by dirtmonkey on Jan 23, 2015 14:46:39 GMT -5
Hey Rick, question on the differences between the newer replacement split bowl and a the AC 572. Which is truely better? I have one of each, the split is on the Jeep now, but have the AC 572 cleaned up and ready to go. Which should REALLY be on my Jeep???
Post by Scoutpilot on Jan 23, 2015 19:45:21 GMT -5
The correct pump would have been a 572. When it went bad, it was rebuilt and reinstalled. Carter's M2195 is a later substitute and is rebuildable as well. If you wanted to upgrade the vacuum system in order to have better functioning wipers, you would have switched over to a double action pump and later on still, electric. From the standpoint of period correct, you would want an original 572 or 2195. The split top is a clone of the 572 and is not rebuildable, but is replaced when it breaks down. In the event the diaphragm failed, it could be replaced, but not the valves, as with the 572 or 2195. The 2195 also has a non rebuildable clone marketed by the Omix, Rugged Ridge and Crown. Kits are readily available for the 572, with an ethanol-proof diaphragm. Rebuilding the 2195 is a different story. For the last four years I have maintained running searches for kits. They are as scarce as the Jeep-in-a-Crate.
If you're asking my preference, I'll go with the rebuildable, original 572 for two reasons. First, it's more correct. Second, rebuilding is cheaper, if you do it yourself, than replacing a clone of dubious quality. The only drawback is the scarcity of good 572's on the market. If you find a good one, take care of it, just as you would the rest of the Jeep. Routine maintenance and care in operation are the keys to longevity.
There is an AC 4032 that has fuel coming out of one of the vacuum ports. I bought an after market replacement for the original (doesn't say what the original was). The replacement is fuel only since I have no vacuum wiper motor. The problem is the inlet and outlet are at 3 and 9 o'clock. The inlet side is pressed against the motor mount arm that is bolted to the front of the motor.
Rick, is there a source for the bowl gasket for the 572? We have a lot of fuel delivery problems in the high country. I'm convinced that most of these problems are because of air leakage into the inlet side of the system, and that half or more of the leaks are at the bowl gasket. Most times the pump is fine but the gasket is bad. BW
I have miles to jeep, before I sleep
Scoutpilot: Cherry pies tomorrow...
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grumpy: No cherry pie thank you, but I will have COFFEE. Off to play in the mud again today, did I mention I HATE MUD, REALLY REALLY HATE MUD. Mud chains are heavy, I dislike chaining up laying in the mud, I f-ing hate mud. Muley likes mud more than me.
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rickg: Did someone say the M-word?
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64cj5: Our mud here in NE Wyoming is Bentonite clay and it is sticky. I am in the Hate Mud group!
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Scoutpilot: Glad none were blown away. Now to keep Y'all from floating away! I've been through that area after a major spring flood. Sleep tight, dry and warm Y'all.
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Scoutpilot: Night boys.
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cline48: John No not yet. The Mighty Mo need some relief. Maybe in two weeks you can let it warm up.
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leemn: Coffee is great!, diet week here!😮, no baked goods as we need to lessen the steering wheel rub! 😮😂😂😎
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oilleaker1: Tired of this key hole to post with. POS.
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grumpy: Oily, I feel your pain I’ve been without my iPad the last couple days just using iPhone it’s a pain. No coffee this morning
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Scoutpilot: Yay! A down-in-the-mouth Oileaker is worse than a Grumpy Grumpy! Good night boys.
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