While pulling the 357 last week I noticed a fluid leak that started to cover the rear end of my truck. it is a 2003 D-max 3500 with just over 100K miles. I could not find the source so I powerwashed the bottom and then ran it and looked for the leak. nothing...I cant find anywhere where fluid is coming from. it does not even puddle on the ground, but if I drive around It starts to cover the underside of the truck again. Any ideas? No seals in the Tranny, Engne, or Rearend are leaking. It is dark fluid.

seems like it would have to be transmission or power steering fluid, check the lines to the tranny cooler, also check power steering hoses, steering box. If all else fails check all fluid levels cold on a level surface. Then recheck after a couple of days. It's going to have to show a loss somewhere.

You didn't say if you have 4X4, if you do then besides the rear end lube, there is the transfer case and front end lube to be considered.

Good luck

EDIT, dont forget the brake fluid level!

I checked the transfer case and front end. Did not think of the brake fluid or power steering.

Thanks

Seems like it must be a hose or a line leaking under pressure and spraying the fluid onto some other component.

Power steering pump also supplies pressure to the brake booster I believe.

I started the truck and crawled under the whole thing trying to find it yesterday. I suspect its a hose, just cant find it.

Axle vent line...

Check your transmission level. If it is over half on the stick you may have vented some trans fluid. Many DMAX owners are filling the trans and when under a load, ie. pulling a heavy boat, the trans will vent a little fluid. It has happened to me. Nothing wrong with the trans, just a little over full.

Sam

This happened to me once while towing. It was a ground problem not allowing the computer to lock up the trans- it blew fluid out of the vent- it was not overfull. I hear GM's are known for this. Go to a good, independent trans shop. I ended up hooking up the boat and taking it on some high-speed hills with the trans guy in the passenger seat with his scan tool connected. Found it right away.

Prater - Didn't know you were here. Talked to you on the OK drag racing forums.
My Ford does this too on the highway empty but worse when full. Tranny gauge never even gets near over hot but it wil still spew. Shop mentioned sometimes electrolisis will eat the bushing where the converter rides and cause a leak under load. Had scanner ran on it unloaded and it showed nothing. Also found in the repair manual there is a solenoid in the tranny that controls lock up and one shop told me solenoid needed replaced. I may run an auxillary ground to mine and try that. Makes a mess of anything under or behind the truck.

That sounds like the problem. Never fails until out of warranty...LOL I will check it this weekend.

Tempest, its a small world

Thanks Again