Cat D5c Magical Leak Fix?

[Dave303223]

So I got my brand new 1993 D5c (SN 6pj00785) home and, as I do, started tinkering with it between clearing some land. I knew it had a pretty bad leak from the trans area but got it at the right price thinking I'd fix it as a winter project then something weird happened. The fellow I got it from said he ran AW32 in everything but the engine and I'm a little picky for spec so changed to TO-4 spec in the Trans and correct Hydraulic in the hydraulics. When I put the new fluid in it leaked like a sieve when running, I worked the dozer about three hours and put it away. Next day I was determined to find the leak, topped it up (didn't take alot) and pulled panels and sprayed it down with cleaner. Got it warm and started looking, a tiny run was coming from around the Right turn brake valve and that was it!

Been working it for two days and still no real leaks, What the heck?? Could just running the right fluid fix a seal leak, swell the seals or lube them? I keep hoping its not a fluke, anyone see anything like that??
Dave

 

[mitch504]

Could it be a leak that leaks when it is sitting and pools in the belly pan, then pours out when you run it? In other words, the little leak you see, just looked bad when you started using it?

 

[Dave303223]

I suppose it could be but according to the previous owner (a construction company) it needs fluid every couple days...by the gallon.

 

[Nige]

There is a major viscosity difference between AW32 (that you mention the previous owner used everywhere) and an SAE30 TO-4 oil for the power train. SAE30 is approximately equivalent in viscosity to an ISO 68. Maybe that had some effect on the leak.?
BTW there is nothing to stop you using SAE10W TO-4 in the hydraulic system if you find some on offer. It won't do it any harm.

 

[Welder Dave]

I've seen hyd. oil that says anti-wear and anti-leak. Apparently has an additive the helps prevent leaks. It meets a bunch of industry specs. If it does help prevent leaks better than standard hyd. fluid, why wouldn't all hyd. have this extra/special additive? Has anyone ever noticed a specific oil, of the same viscosity and specs., not leaking as much as a different brand? If it was actually proven to help with leaks might be worth the extra $19 per pail. I'd suspect it's just a marketing ploy to get the extra $10.

 

[Dave303223]

Not hear of that fluid before, might try it for a farm dozer but I like to fix the leaks if can. Nige, at the cost of TO-4 I think I'll keep using AW46 in the hydraulics, can you imaging changing out 15 gallons! I'm guessing it can be mixed with the AW though?
It is still leaking but I just can't nail it down, thought it was coming from the right break control valve but it doesn't leak until you are working the dozer. I had my wife look in there while I moved it slowly and turned left and right but could not see where it was coming from!! It is the wettest by the right valve but also was slinging off the PTO joint. I need a little camera down there!
Dave

 

[Welder Dave]

15 gallons is 3 pails. Not too big an expense relatively. Imagine changing the oil on Big Muskie. It held 26,000 gallons of hyd. oil!

 

[Mcrafty1]

Not hear of that fluid before, might try it for a farm dozer but I like to fix the leaks if can. Nige, at the cost of TO-4 I think I'll keep using AW46 in the hydraulics, can you imaging changing out 15 gallons! I'm guessing it can be mixed with the AW though?
It is still leaking but I just can't nail it down, thought it was coming from the right break control valve but it doesn't leak until you are working the dozer. I had my wife look in there while I moved it slowly and turned left and right but could not see where it was coming from!! It is the wettest by the right valve but also was slinging off the PTO joint. I need a little camera down there!
Dave

Not affiliated but I do buy my TO-4 oils from these people, last I purchased they were still doing free shipping to your door, I don't know how much longer they will still be offering that.
https://buysinopec.com/products/to-...uid-5-gallon-pail?_pos=1&_sid=727394ce1&_ss=r

 

[Dave303223]

Welder, now I know why I see all those buckets at construction sites,
That's not a bad price if it's free shipping, I looking at my tractors and backhoe to see if I can consolidate to TO-4 in them. My Yanmar uses TO-2 so I'm pretty sure it can use -4, not so sure about the old Case backhoe.

 

[Mcrafty1]

QUOTE="Dave303223, post: 1088688, member: 118963"]Welder, now I know why I see all those buckets at construction sites,
That's not a bad price if it's free shipping, I looking at my tractors and backhoe to see if I can consolidate to TO-4 in them. My Yanmar uses TO-2 so I'm pretty sure it can use -4, not so sure about the old Case backhoe.[/QUOTE] TO-4 is the upgraded T0-2