Cat D8 1955 15A Questons

Q1-The seals on the TC are supposed to leak. And when it gets to (I think) 13 drops per minute, it's time to pull the TC (check when running). If it leaks while sitting, they need, it needs fixing . If you do it now, the most you'll run into are 2 bearings and 2 seals. Run it to long and you got BIG TROUBLES. They used to make a kit for rebuilding the seals, a whole lot cheaper than buying new seals. I don't have that number anymore, sorry.

Q2- Sounds like you need to adjusdt the pony motor clutch....just guessing.

Q3- Sounds like the pinion bearings on that side are about to go out. And yes, the brake drums are a little trouble to get to but not that bad. If the dozer has a cab on it, just throw a chain around the cab to do the heavy lifting. I usually just made 2 loops in the chain and suspended a large pipe between the loops to hang a come-along or chain hoist from it.

It's not so much that they are supposed to leak, although some is inevitable, it's that there is provision for drainage from the front and rear seals. Do not plug the drains. If the drainage is blocked the leakage will go where you don't want it, like into the clutch. The service manual states that up to 10 drops per minute while operating is satisfactory, more when cold.

Yes, you need a pony clutch adjustment. It is apparently slipping.
Take the cover off the clutch section, turn the adjusting collar until you find the lock pin. Pull the lock pin out and turn the collar to the right until the lock pin drops into the next hole. Repeat until you get a good engagement, better a little loose than to tight.

A worn out brake lining or missing lining section can also pulse the pedal.

When I bought my 15a it was in the fall and I heard it run and made the deal. I couldn't pick it up right away and by the time I did it was REAL cold. We could not get it to turn over no matter what we did. Finally we realized that the plug in the bottom of the clutch housing that has a hole with a cotter pin in it was plugged solid and the flywheel was submerged in about 6" of ice. Once we got it thawed it fired right up. Live and learn.
Packrat

wow.... thanks for the replys! Its reassuring to know there are some folks here that know about this tractors. I don't know anyone else to ask about this stuff.

What is working on the torque converter like? Is there any special tools or knowledge I would need? Any ballpark guess on what the parts would run? A few hundred bucks? I'm only 24 and not exactly making millions yet😛

I will look into adjusting the pony motor clutch. Hopfully its that simple. Never adjusted that myself, so who knows how long its needed attention.

A pinion bearing sounds scary. Dare i ask how you put one of those in? I have visions of having to split the track......
What the best way to trouble shoot the pedel issue? A brake liner doesn't seem to critial, but a pinion bearing sounds catastropic.

I don't have a proper service manual for a 15A - I have one for a 35A-36A 46A. Some stuff looks similar, alot looks competly differnt. I think i'll head over to eaby and look for a 15A manual now.....

Edit - What is my service manual going to look like? I see alot of the one I have on ebay, with the serial numbers it covers printed on it, but then theres a couple that don't have any serial numbers given, like this one - http://cgi.ebay.com/CATERPILLAR-D8-TRACTOR-SERVICE-REPAIR-MANUAL-1955_W0QQitemZ7623864205QQcmdZViewItemQQptZBI_Books_Manuals?_trksid=p3286.m20.l1116

Does the 15A manual say 15A on it anyplace?

Thanks for any advice you guys can provide.

Other than the usual gear and bearing pullers no special tools are required to work on the converter......just big, heavy and awkward grunt work.

Yes, Cat was dumb enough to publish service manuals without model, serial or form numbers.🙄

Helps to know the production year ranges and when materials might have been printed. A D8 manual for 1955 could be for a 13A model (53-55)
The manual I have does state for the 14A and 15A models on the first page (if it's not missing)(54 - 5😎 and is made up of sections printed in 1955-56-57 & 58.
The models you mention are quite similar in detail

Yes, pinion bearings are a major job......need access to both inner (through steering clutches) and outer which has cover plate access from the outside if you can push the bearing out.....otherwise you would need to brake the chain, remove the sprocket (requires track truck removal) and final drive gear case.

Can't help you with costs.
I'd try tracking down the needed parts first.

Other than the usual gear and bearing pullers no special tools are required to work on the converter......just big, heavy and awkward grunt work.

Yes, Cat was dumb enough to publish service manuals without model, serial or form numbers.🙄

Helps to know the production year ranges and when materials might have been printed. A D8 manual for 1955 could be for a 13A model (53-55)
The manual I have does state for the 14A and 15A models on the first page (if it's not missing)(54 - 5😎 and is made up of sections printed in 1955-56-57 & 58.
The models you mention are quite similar in detail

Yes, pinion bearings are a major job......need access to both inner (through steering clutches) and outer which has cover plate access from the outside if you can push the bearing out.....otherwise you would need to brake the chain, remove the sprocket (requires track truck removal) and final drive gear case.

Can't help you with costs.
I'd try tracking down the needed parts first.

One guess about the pumping brake pedel is the brake drum is loose on the final pinion shaft. On some cats you can take off an inspection cover off the back of the case. If so you can put a pry bar in and see if the brake drum moves up and down. If so it's loose on the pinion shaft. The manual for a 15A is smaller than the one you show. I wil look through my stuff today and see if I have one, I think I do. Charlie

yeah.... I was thinking the 15A had a drum brake, can't remember who told me that. I'd imagine if its loose it screws the splines on the shaft and the drum all up?

If you have a 15A manual you would like to part with, let me know, I would probably be interested😄 Or even if you could just post a picture of it so I can get an idea what the cover looks like.

One more question....are your steering clutches wet or dry? (meaning do they run in oil or not)