for a 13-3-53 CDN Jeep
 

Trying to help a new Jeep owner who lives down the roads from me.

First question...... engine runs for five minutes then the oil pressure drops to zero...... using HD 40 or 50. Pan been removed screen and pan bottom cleaned..... sludge was present but not an issue. No Knocking yet from the engine....runs reasonably well for the first 5 minutes. We have a new oil pump that we may try to install....? 61k on the clock so the engine may be very worn out. No history on the vehicle except that it was used on a farm....!!!!

Second question..... looking for a picture of the engine compartment that will show the routing of the fuel line from the pump to the carb.....
....the current fuel line goes from the pump on the driver's side across the front to the pass. side up and over the engine back to the carb on the driver's side...

Present set up looks ridiculous and plastic inline fuel filter crammed in a hot environment........ to me it would make more sense to runs directly from the left side pump to the left side carb with a proper period glass bowl filter.
Comments......??? and would use steel brake lines rather than copper.

Not enough to do with CMPs now playing with a Jeep.

contract number is LV 600 ARMY....... stamped "M38A1 CDN" no idea if the engine is original to the jeep....... no lifting hook on the block!!!!

Bob C.

Bob. With that much fuel line under the hood is it vapour locking?

David

Bob: The date is unusual. You say 13-3-53 however the typical format was Month-Day-Year. Is this M38A1CDN possibly 3-13-53 ? Any chance you know the Ford serial F-xxxxx.

Vapors??? dates....
 

Hi David

Never ran it long enough to get hot ...... within 5 or so minutes the oil pressure started to go to zero so it was turned off........ however in its present location I would be really concerned for fuel to boil/vapor or melt the plastic housing of the filter.

On the dates.... yes you are correct Brian.... it is March 13 53..... where will I find the engine serial number??? not sure the engine is original of the 53 jeep???? will the engine serial be on the data plate...?

All the data plates are on the dash but very difficult to read partly worn and bad eyes..... best to HiRez photograph then play with photoshop to make out the faint lettering/stampings.

Thanks

Bob C

jeep
 

Hi Bob , take a couple of photos of the engine area and send them to cckw353@bell.net , then call me,

Photos
 

Will do Frank probably tomorrow.....

Thanks

Meanwhile back on the web.....
 

Found a lot of very useful information on the web......history of the Hurricane and specs..... numerous forums discussing low oil pressure and sludge build up...... and lots of pictures helping me sort out the filter connection and solution for the one oil leak we noticed at the block where the line exits to go to the filter...... well hidden behind the two stage fuel pump.

Will try to take pictures of the actual jeep in question tomorrow.

Grant is doing a search of his technical book library.

I can see someone falling in love ( not me.... not me) with the cute little thing....after slugging on the CMP oversized parts....... the bare power train pictures of a jeep is cute and cuddly.... makes you want to pick it up and burp it!!!!!

My preliminary plan of action...........

A... install a mechanical oil pressure gauge and see the results......

B....followed by changing the oil pump (owner already has a new one).......all hoping to save the engine from a tear down.

Cheers

In my limited experience, the F-head engine gave about 15000 to 20,000 good miles, followed by about 15,000 bad miles and then you replaced the engine. I was going to suggest a mechanical gauge, but I see you've already figured that out.

One of the weaknesses of the Jeep blocks is that there is only one replaceable bearing for the cam. The remainder of the cam supports are the block itself, which means any wear in that location will not be fixed by merely turning the crank, new bearings, and replacing the one cam bearing.

That said, oil pressure is highly overrated. I worked on one engine recently where the owner had the motor rebuilt, but could get no real oil pressure reading. They changed the sending unit, then changed the gauge, then changed the sending unit....

Anyway, going along on the highway, the engine suddenly seized up solid. When I tor it down, I found that the re-builder had neglected to put the front oil nozzle back in (sprays oil against the timing gears), thus leaving a 3/8 hole wide open on the main oil gallery. And yet, the engine had survived several years like that.

If it does come to a teardown, they are a great little engine to work on. I used to do them in my basement back in the old days. The problem was getting the finished product back up the stairs.

The fuel line does indeed run across the front of the engine, then up and across to the carb. My guess is it keeps the line away form the exhaust manifold. Personally, I have never had an issue with vapour lock on the Jeeps. Best place for the filter is down at the frame before the fuel pump.

Good tip......
 

Thanks Rob.

We have a spare 24v sending unit as well as a mechanical oil guage to start with...... then we will tackle the pump replacement.

At 61K on the clock, assuming it is the original block, it may be tired.

Thanks for the tips.....will post results.

Bob C

The serial number for the block should be on top of the water pump on a little flat surface there. If it is a military engine, it should start with MD

No numbers.....
 

...area is smooth as a baby's bottom.... will try removing the grey paint but doubt there are any indentation/numbers...... which would mean?????

Will be tackling the pump, leaking oil line and a mechanical gauge next Wed.

The owner will prep. the patient by jacking up on stands, removing the fender and front tire..... then we get dirty!!!!

need to work on the photos we have taken today.

Cheers

No numbers means a replacement block, most likely post service.

Here comes the pictures and questions.....
 

will need to do in two postings.

Part two......
 

Would appreciate comments on the ID tag...

...........thanks for all your help guys.

Next Wednesday we operate!!!!!

Carb
 

The carb is a Carter YS950S; standard fitting for the M38A1. :teach:

Owen.

In your photo "input line to fuel pump", the line you show is actually part of the vacuum system. The bottom half of the pump is for vacuum. The fuel pump is the upper half of the pump. It looks like yours has a heavy rubber line feeding the fuel in. That is a good candidate for a fuel filter as it will catch the crud before it goes into the little check valves of the pump, causing it to just idle rather than pump. The crud is usually minute rust particles from the tank.

The ring on the spring was added as part of a kit for air transport. It provided about a dozen rings on the frame, springs and bumpers to allow tie down on the aircraft pallets.

Re the 2 screws on the distributor, there was usually more than two and less than six. Personally, I prefer the higher end of that range, but when you are trying to diagnose an ignition problem at the side of the road, and the sharp little fording cable (among other things, including frayed ignition wires) have repeatedly poked through your skin, drawing blood, one can lower one's standards a little. You will find those screws need a couple different screwdrivers to install due to the awkward angles. And if you think working on a 53 is tough, wait until you work on the later ones with the big honking heater and tray blocking your access.

The grey paint on the engine, right over the grease and dirct accumulations, is the sign of a poor man's overhaul. We used to have another name for that kind of rebuild, but it is no longer politically correct. In fact, I doubt it ever was.

oil pump
 

Hi Bob. I agree with your note on the photo of the oil pump. Taking a couple of minutes to drop that section of exhaust pipe from the manifold to the first bolted flange by the master cylinder, will give you some much needed space for your hands and tools when removing and installing the pump.

If you don't already have it, below is a clip from the manual. Paragraph E-92 may be of interest. You can install the oil pump without removing the distributor, but getting the pump gear to slide up and mesh on the camshaft in the right position can sometimes take a couple of tries and a bit of patience (and holding your tongue in the right position :p). If you are able to reference the position of the slot when you remove the pump, it will help to index it to the right position when re-installing.

Final results for now!!!!!!
 

Jeep is running on 5 pounds oil pressure once warmed up and idling, goes up to 20 pounds once you blip the throttle.

Here is what Grant and I did.....

We replaced the old cracked flex line with a steel line custom shaped between the block and the oil filter....

Managed to puncture the radiator tank with the fan blade( not much support on the rillonce the fenders are removed..... got it soldered and reinstalled with new coolant and a new bottom rad hose.

Removed the oil pressure sender and replaced with a mechanical gauge which is much more accurate ........ now showing 5 pounds idling when hot 20+ when throttle if blipped.

Owner wants to drive it for a while and monitor the oil pressure gauge. To facilitate that we will permanently install a mechanical oil pressure gauge which seems more sensitive and accurate,

Based on the light Blue smoke and low pressure the engine is probably due for a rebuild as a Winter project...... meanwhile he can enjoy it giving rides to the grandson or go to town for an ice cream cone.

We still have to replaced the short flex fuel line to the pump which has become very spongy.

As a Winter project in a small heated garage the wiring harness may also be tackled.

So we had fun......and possibly more fun to come.

Thanks for all you help guys

Five and twenty hot is still serviceable.

Ideally, compression should be around 120. It will still give OK service to around 110. By 90 it will be impossible to start in the fall without ether and will use plenty of oil. The pistons have a lot of travel, and scored up bores is the norm on those engines.

This Thread is a good read
 

Hi All


Just read this thread form the start, just plain a good read, sharing of a problem, possible solutions, and results of the effort.


Like the idea of getting a vehicle running and enjoyable before starting to take it all apart to restore.


Cheers Phil

Read some more Phil......
 

Owner drove around his farm and said it bothered him that the longer it ran the lower near the ZERO oil pressure everytime he idled...... and only went up to 15 or so when driving at low speed.....

So out went the pump.... and after about 20 tries we got the new pump back in properly engaged...... have yet to start the engine...... had to disconnect the exhaust pipe for clearance and now hunting for a exhaust gasket or material to make some...... need to hear it run by tonite and see if the oil pressure is better or same...

Stay tuned....... my break is over......

So the goose is cooked....
 

Got everything bolted back on the jeep and she started right up....oil was at 25 pounds cold....... it did take longer for it to go down but down it went. After 15 minutes we had 3 or 4 pounds on the mechanical gauge..... back to 20 at a fast idle..... engine runs smooth no knocking or missing.

With much regret the owner and I have agreed that the next step will be a tear down and rebuild during the cooler months of the Fall Winter. Safe to give the grand kids rides but only on the farm.

Except for the fishing to get the pump back in the same timing position of the distributor, the job is technically relatively easy. so now we have a new pump and can plan rebuilding an engine around it...... dropping the exhaust pipe is a must for hand clearance. 3 hands are a must as someone has to hold the rotor by hand in the same original position while inserting the pump.

Off for a few weeks at a cottage but when I return I will be tackling my slipping clutch problem on the C15A ....