Ford NAA Hydraulic won't lift. Also has a noise in the transmission like a bad bearing or rough gear.

[thelonepatriot]

I bought this tractor at an auction so I don't know the history of it but has been used hard and has been through several auctions. I bought it not running for $500. I got my money's worth in the near new condition tires (4) and one new rear rim. I finally got it started today.The hydraulic won't lift at all. I tried it with the draft control in both positions. I have an owner's manual and the Ford Tractor NAA service manual. I get the impression that there are three oil levels that need to be checked, Transmission, hydraulic, and differential. Is this correct? I did pull the dipstick and it has oil in it. I don't think the noisy transmission has anything to do with the hydraulic issues. This tractor has a sherman transmission that may be the source of the noise. The gearshift is held in the upper position with a spring. I have only driven the tractor a few hundred yards because of the noise.

Are hydraulic pump parts still available? Also, where can I get a wiring diagram? I lust hot wired it to get it started.

 

[JMOR]

I bought this tractor at an auction so I don't know the history of it but has been used hard and has been through several auctions. I bought it not running for $500. I got my money's worth in the near new condition tires (4) and one new rear rim. I finally got it started today.The hydraulic won't lift at all. I tried it with the draft control in both positions. I have an owner's manual and the Ford Tractor NAA service manual. I get the impression that there are three oil levels that need to be checked, Transmission, hydraulic, and differential. Is this correct? I did pull the dipstick and it has oil in it. I don't think the noisy transmission has anything to do with the hydraulic issues. This tractor has a sherman transmission that may be the source of the noise. The gearshift is held in the upper position with a spring. I have only driven the tractor a few hundred yards because of the noise.

Are hydraulic pump parts still available? Also, where can I get a wiring diagram? I lust hot wired it to get it started.

https://imgur.com/PVpk8MI

 

[mhb@ufe]

I bought this tractor at an auction so I don't know the history of it but has been used hard and has been through several auctions. I bought it not running for $500. I got my money's worth in the near new condition tires (4) and one new rear rim. I finally got it started today.The hydraulic won't lift at all. I tried it with the draft control in both positions. I have an owner's manual and the Ford Tractor NAA service manual. I get the impression that there are three oil levels that need to be checked, Transmission, hydraulic, and differential. Is this correct? I did pull the dipstick and it has oil in it. I don't think the noisy transmission has anything to do with the hydraulic issues. This tractor has a sherman transmission that may be the source of the noise. The gearshift is held in the upper position with a spring. I have only driven the tractor a few hundred yards because of the noise.

Are hydraulic pump parts still available? Also, where can I get a wiring diagram? I lust hot wired it to get it started.

If the gear shift lever is held in the upper position with a spring it would have to be a 5 speed transmission which was never available in the NAA. But I have never seen a 5 speed with a sherman.

 

[thelonepatriot]

Thanks JMOR. I will print a copy.

 

[thelonepatriot]

I should have proof-read my posting better. It is the Sherman gearshift that is held up by the spring. My tractor is a 4 speed.

 

[Sean in PA]

If the gear shift lever is held in the upper position with a spring it would have to be a 5 speed transmission which was never available in the NAA. But I have never seen a 5 speed with a sherman.

I think that he was talking about the shifter for the Sherman being held up by a spring.

 

[mhb@ufe]

I should have proof-read my posting better. It is the Sherman gearshift that is held up by the spring. My tractor is a 4 speed.

That makes more sense and that would have the sherman in overdrive and it is not uncommon for them to be noisy in overdrive. have you tried other gears in the sherman?

 

[Fordfarmer]

I bought this tractor at an auction so I don't know the history of it but has been used hard and has been through several auctions. I bought it not running for $500. I got my money's worth in the near new condition tires (4) and one new rear rim. I finally got it started today.The hydraulic won't lift at all. I tried it with the draft control in both positions. I have an owner's manual and the Ford Tractor NAA service manual. I get the impression that there are three oil levels that need to be checked, Transmission, hydraulic, and differential. Is this correct? I did pull the dipstick and it has oil in it. I don't think the noisy transmission has anything to do with the hydraulic issues. This tractor has a sherman transmission that may be the source of the noise. The gearshift is held in the upper position with a spring. I have only driven the tractor a few hundred yards because of the noise.

Are hydraulic pump parts still available? Also, where can I get a wiring diagram? I lust hot wired it to get it started.

Hydraulic pump parts are available. This site sells parts, kits, and complete pumps. Do you have a piston or vane pump? The vane pumps were original equipment, but many, if not most, have been replaced over the years with piston pumps. Here's a piston pump kit. https://www.yesterdaystractors.com/Ford-NAA_Hydraulic-Pump-Repair-Kit_CCPN600AB.html

 

[Jim L WA]

The hydraulic pump may have lost prime. To check, disconnect the smaller (pressure) tube from the pump and turn the engine over with the starter. If no oil flows out apply air pressure to the oil dip stick hole. Hopefully that will solve it.

 

[thelonepatriot]

The hydraulic pump may have lost prime. To check, disconnect the smaller (pressure) tube from the pump and turn the engine over with the starter. If no oil flows out apply air pressure to the oil dip stick hole. Hopefully that will solve it.

I will try what you suggested. Thanks.

 

[thelonepatriot]

I removed the fill plug in the transmission cover. It has oil in it but it looks to me like it is low. The dipstick is at the full mark. Does the differential have its own reservoir? There is a fill plug on top of the differential housing. It does have oil in it but I'm sure it is low. I took a pipe plug out of the left axle trumpet near to where the lift link is fastened on to check for oil. I used a small stick to check for oil in it. I put it about 2 inches deep and it came out dry. Am I supposed to fill the differential until it runs out there? There is almost zero information in the owner's and service manuals.

 

[mhb@ufe]

I removed the fill plug in the transmission cover. It has oil in it but it looks to me like it is low. The dipstick is at the full mark. Does the differential have its own reservoir? There is a fill plug on top of the differential housing. It does have oil in it but I'm sure it is low. I took a pipe plug out of the left axle trumpet near to where the lift link is fastened on to check for oil. I used a small stick to check for oil in it. I put it about 2 inches deep and it came out dry. Am I supposed to fill the differential until it runs out there? There is almost zero information in the owner's and service manuals.

Yes, that is the level plug for the rear axle.

 

[thelonepatriot]

The hydraulic pump may have lost prime. To check, disconnect the smaller (pressure) tube from the pump and turn the engine over with the starter. If no oil flows out apply air pressure to the oil dip stick hole. Hopefully that will solve it.

I took the pressure line off and found some water droplets. I cranked the engine over and there was no flow. I took the inlet line partway down and blew air in the dip stick hole and blew oil and some water out. I then put the inlet line back on and blew air in the dip stick hole and it blew more oil and water through the pump. (The pressure line is still off at this point.) I started the tractor and it still didn't pump any oil out. I didn't rev the engine up because I didn't want oil spraying all over in case it did pump. I'm thinking the vanes may be rusted in place. Hopefully they will break loose if I rev the engine for a while. Is it possible to buy just the vanes for the pump?

Jim, thanks for your advice.

Where do I check the transmission to see if it is full? I don't want to loosen the wrong thing and have something fall apart.

 

[thelonepatriot]

That makes more sense and that would have the sherman in overdrive and it is not uncommon for them to be noisy in overdrive. have you tried other gears in the sherman?

I took the tractor for a short drive this afternoon. In direct drive there was no excessive noise. When I got back I tried it in the yard with the main transmission in neutral. There was a lot of noise in high range and some noise in low range. I think I will look for some type of oil additive to pour in it.

 

[Sean in PA]

I took the pressure line off and found some water droplets. I cranked the engine over and there was no flow. I took the inlet line partway down and blew air in the dip stick hole and blew oil and some water out. I then put the inlet line back on and blew air in the dip stick hole and it blew more oil and water through the pump. (The pressure line is still off at this point.) I started the tractor and it still didn't pump any oil out. I didn't rev the engine up because I didn't want oil spraying all over in case it did pump. I'm thinking the vanes may be rusted in place. Hopefully they will break loose if I rev the engine for a while. Is it possible to buy just the vanes for the pump?

Jim, thanks for your advice.

Where do I check the transmission to see if it is full? I don't want to loosen the wrong thing and have something fall apart.

If the vanes are rusted in place, the pump would not spin at all, and something would break, most likely the woodruff key on the shaft, but possibly the splines in the rotor, or even the teeth on the driving or driven gear, or the vanes themselves. I recommend dismantling the pump to see if there are parts that can be replaced, as some of the parts for the vane pumps are no longer available, or you can bite the bullet and convert to a piston pump.

 

[thelonepatriot]

If the vanes are rusted in place, the pump would not spin at all, and something would break, most likely the woodruff key on the shaft, but possibly the splines in the rotor, or even the teeth on the driving or driven gear, or the vanes themselves. I recommend dismantling the pump to see if there are parts that can be replaced, as some of the parts for the vane pumps are no longer available, or you can bite the bullet and convert to a piston pump.

The tractor isn't worth a new pump. It has been used and abused a lot. The top link rocker has been broken out of the rear end housing and welded back in with a lot of weld area. The rear fenders have been replaced with non-scrip fenders so I'm guessing whatever happened to break the rocker loose also took the original fenders out. The transmission housing has a large patch welded in around the sherman gear shift and extending back about 10 inches. I think for now I'll just remove the pump and cover the openings and watch for another NAA. In the mean time I can drive it around for transportation with the highspeed Sherman. I don't have a driver's license due to having Parkinson's Disease but they can't stop me from driving my tractor. For now, I have a huge squash patch to pick before the first killing frost. Last Sunday I counted well over 100 squash and that's just the ones I could see. There are a lot more beneath the leaves.

 

[Keith Williams]

The tractor isn't worth a new pump. It has been used and abused a lot. The top link rocker has been broken out of the rear end housing and welded back in with a lot of weld area. The rear fenders have been replaced with non-scrip fenders so I'm guessing whatever happened to break the rocker loose also took the original fenders out. The transmission housing has a large patch welded in around the sherman gear shift and extending back about 10 inches. I think for now I'll just remove the pump and cover the openings and watch for another NAA. In the mean time I can drive it around for transportation with the highspeed Sherman. I don't have a driver's license due to having Parkinson's Disease but they can't stop me from driving my tractor. For now, I have a huge squash patch to pick before the first killing frost. Last Sunday I counted well over 100 squash and that's just the ones I could see. There are a lot more beneath the leaves.

If I understand correctly, the sherman aux trans gets its oil from the main trans when the oil is splashed around.
With the kind of damage you have described, I wonder if it can hold oil anymore and is in fact just running dry?
Keith