Ford NAA Distributor/Oil pressure problem

[tmajor]

Hi,
I just changed out my NAA distributor with a used one. Tractor starts and sounds good. While taking it for test spin, I noticed that it didn't seem to have any oil pressure. It never did have terrific pressure, especially when warm ... but it did have some.

According to the manual, the distributor can't be fully seated, unless the end of the dist. shaft drops into the oil pump slot. Is this for sure?

I didn't compare the length of the shafts, but assumed it was correct, as I believe the NAA was the only dist. with a straight tang on the end to fit into a slot in the oil pump. Plus, it was represented as a NAA dist..

Thanks, Tom

 

[tmajor]

The distributor won't seat fully, until the shaft drops into the oil pump slot.

After checking the distributor shaft length, and finding it to be correct, I tested the oil pressure gauge, which seemed OK. So, at this point, I'd say the oil pump has gone south.

 

[Soundguy]

odd that it would just up and die while setting.

Normal procedure is to investigate rapid drops in oil pressure, vs gradual ones which are usually wear, etc. going from some, even if not great, to nothing sounds odd.

I'd pull the oil pump and inspect and check the relief valve.

what was your oiul pressure before failure?

most 134/172 engines I see that are not worn slap out usually make good pressure 40-55psi. My most worn 172 engine will make 40 psi cold, and 28 hot idle.. and it's been run hard and put away wet long before I got it.

post back

soundguy

 

[tmajor]

Like I said, it has never had good or uniform pressure ... I'd guess, 30 lb. was about max, when cold, .. maybe 10lb. when hot. The guy I bought it from, said the pressure had always been low.

I've got a new pump on the way, but I'll look things over, when I get the pan down.

 

[Soundguy]

that's dismal for a OHV red tiger engine... I'm not sure I've ever seen a runner with that low of pressure...

check the pump pickup tube as well..

 

[tmajor]

I think, I've discovered the problem.

This morning, after breaking two studs off, while removing the pan, I got the pump removed. I didn't see anything wrong, until I took a look at the check valve or pressure valve, which ever it is. The valve was half way across the hole. Not being familiar, I tried to push the piston back with a screw driver, which didn't do anything. Then I removed the cap and spring, applied some WD-40 and played around with the piston. Finally, I was able to tap it in further, but it was tight! Eventually, I got it worked out of the pump body. The piston was a little varnished, but I noticed a pretty significant, 1/2 moon wear ridge, which would correspond with the pump hole, on the piston. I don't know why it froze fast ... whether it was the varnish or whether the wear ridge had gotten turned a bit. Regardless, it was frozen in place.

I can't imagine, the changing of the distributor, having anything to do with the oil pressure issue.

 

[Soundguy]

at least now you know!

soundguy

 

[tmajor]

I received the oil pump today ... it seemed to take longer to get here, than I expected.

It seemed to be short one gasket for the pick-up tube to oil pump, ... I made that. When I got the pump in place, I couldn't get a wrench on the rear nut to tighten. I had to pull the pump back out and grind some of the casting back, more like the original equipment. After that, it pretty much went together OK ... drive shaft to the distributor was a little snug, mating up.

Ready for the test! I was told to crank the engine over a bit, without starting, to prime the pump and get some pressure. That didn't seem to do the trick, so I fired it up. It probably took 30 seconds for the pressure to start to climb. Warm, at decent RPM, it has about 42 lbs. and about 20 lbs, at a real low idle.

So, I believe, it's ready to go.

 

[Soundguy]

dang.. still low at idle.. I'm surprised.. those engine usually make better pressure than that... even worn..

soundguy

 

[tmajor]

The NAA has run good this summer, with the exception that the water pump went south.

As I was brush hogging, I noticed quite a few hayseeds stuck on oil on the right side of the engine. I haven't examined it carefully, but I believe, oil may be coming from the distributor to block connection. I thought maybe, there should be a gasket between the dist. and block, but I don't see any such part or application.

Like I said, I didn't examine it carefully, but the oil was pretty far forward and spread toward the back of the engine.

Anybody had this problem or know anything about it and it's cure? Would a gasket under the dist. mounting be any problem?

 

[Soundguy]

clean it up and take a look as to where it is coming from.

134372 O-RING O-Ring, 1.109" ID x .139" Thk, Base to Block

soundguy

 

[tmajor]

Is that a Ford number or standard stock number? Have you done this, with results? Thanks.

 

[Soundguy]

that's from the ford master parts catalog.

yep it's pulling yer distrib if that's what you are asking..

if it was a small seep.. i might clean up with a spray cleaner / carb cleaner and see what a lil bead of rtv might do..

soundguy

 

[tmajor]

I'll clean it up and go with the O-ring install or replacement. I still have the old dist., so can check that first. I don't remember seeing one, when I dropped the new dist. in .. it could be there or not.

Thanks! :thumbsup:

 

[Soundguy]

I'll clean it up and go with the O-ring install or replacement. I still have the old dist., so can check that first. I don't remember seeing one, when I dropped the new dist. in .. it could be there or not.

Thanks! :thumbsup:

here's the exploded parts diagram and parts list... part #8 is the oring I posted

1 FAC12127D DISTRIBUTOR Distributor Assy., L/Term Housing & Rotor, NAA, Includes: Ref. 3 thru 25, Years: 01/01/1953-12/31/1954
1 86588846 DISTRIBUTOR Distributor Assy., Includes: Ref. 1, 2 & 3 thru 25, Start Year: 01/01/1955
1 1 NCA12106A HOUSING Housing Assy., Distributor Cap
1 1 86588847 CAP ASSY. Cap Assy., Distributor, Use with 86588846 Distributor
2 1 C0NN12200A ROTOR Rotor Assy., Distributor
2 1 86588848 ROTOR Rotor, Use with 86588846 Distributor
3 1 311457 BASE Base Assy., Distributor Includes: Ref. 4 thru 6
4 1 7RA12132A BUSHING Bushing
5 1 8EQ12135A Oiler Assy., Replaces P/N FAB12135A
6 1 4012141 WICK Wick, Shaft
7 1 D8NN12A118AA SEAL Seal, Shaft Oil
8 1 134372 O-RING O-Ring, 1.109" ID x .139" Thk, Base to Block
9 1 FAA12179A THRUST WASHER Washer, Gear Thrust
10 1 FAD12390A GEAR Gear, Distributor Driven
11 1 PL PROCURE LOCALLY Rivet, Round Hd., 1/8" x 7/8"
12 2 7RA12144 CLAMP Clamp, Terminal Housing
13 2 B12145 RIVET Rivet, Terminal Clamp, No Longer Serviced
14 2 FAA12270A CLAMP Clamp, Base, No Longer Serviced
15 2 PL PROCURE LOCALLY Washer, Lock, 5/16"
16 2 PL PROCURE LOCALLY Bolt, Hex, 5/16"-18 x 1"
17 1 8N12209 ELEC CONNECTOR Conductor, Primary
18 1 7RA12234 INSULATOR Insulator, Primary Terminal
19 1 7RA12233 BUSHING Bushing, Primary Terminal
20 1 PL PROCURE LOCALLY Washer, Flat, #10
21 1 PL PROCURE LOCALLY Nut, Hex, #10-32
22 1 350032S SCREW Screw, Brass, #10-32 x .84
23 1 FAC12175C SHAFT Shaft Assy., Distributor, Years: 01/01/1953-12/31/1954
23 1 311460 SHAFT Shaft Assy., Distributor, Years: 01/01/1955-12/31/1964
24 1 FAA12176A ADVANCE DEVICE WEIGHT Cam & Weights Assy., Distributor, Years: 01/01/1953-12/31/1957
24 1 NSS NOT SERVICED SEPARATELY Cam & Weights Assy., Distributor, Years: 01/01/1958-12/31/1964
25 1 166978 SNAP RING Ring, Snap, #37, Ext, Cam
26 1 FAD12152A PLATE Breaker, Distributor Base
27 2 PL PROCURE LOCALLY Screw, & Lockwasher, #8-32 x .38, Breakaway Assy., to Base Fillister Hd.
28 AR CPN12000A KIT Kit, Point & Condenser, Includes: Ref. 29 & 30
29 1 D8NN12171AA ARM Arm & Bracket Assy.
29 1 86588849 BREAKER POINTS Points, Use with 86588846 Distributor
30 1 86500249 CONDENSER Condenser Assy.
30 1 86588850 ASSEMBLY Condenser, Use with 86588846 Distributor
31 AR 57683S36 SCREW Screw, Pan Hd, W/Washer, G5, #8-32 x 1/4"
1 PL PROCURE LOCALLY Screw & Lockwasher, Fillister Hd., #8-32 x .19, Condenser to Breaker Plate
2 PL PROCURE LOCALLY Screw & Lockwasher, Fillister Hd., #8-32 x .19, Arm & Bracket
32 2 PL PROCURE LOCALLY Washer, Lock, #6
33 2 PL PROCURE LOCALLY Nut, Hex, #6-32
34 1 86588587 COVER Cover Assy., Breaker Dust, Includes: Cover, & Ref. 35 thru 37
35 1 FAA12114A GASKET Gasket, Cover to Base
36 1 FAB12267A SEAL PROTECTION Seal, Cover
37 1 FAA12268A RETAINER Retainer, Cover Seal
38 1 8N12213 CLIP Clip, Rotor Spring
39 AR 309787 KIT Kit, Tune-Up, Gasoline, Includes parts numbered 39, Not Illustrated
39 1 CPN12000A KIT Kit, Point & Condenser
39 1 C0NN12200A ROTOR Rotor Assy.
39 1 8N12213 CLIP Clip, Rotor Spring
39 1 86548828 SPARK PLUG Spark, Plug
39 1 309789 GAUGE Gauge, Point Setting
39 1 309790 GREASE CARTRIDGE Capsule, Cam Lubricant

 

[tmajor]

How come, you didn't have an "add to cart" button with the breakdown and parts list? :laughing:

Thanks again.

 

[Soundguy]

gotta leave soemthing for you to do..