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C-Leigh Racing · 06-01-2012, 09:02 AM

99 V10 4R100 trans.
Installed an extra fluid cooler along with an inline filter in the return line back to the trans.
On this M/H, the fluid lines from the transmission go direct to the OEM fluid cooler & back to the trans, not through the radiator & then to the cooler.

The extra cooler is added in on the return line from the OEM cooler back to the trans.
Nothing was touched on the trans far as fluid lings or fittings, other than the test port plug removed & then installed a sender unit for a temp gauge.
That was all has been done.

Now for some reason, there is a small fluid leak at the rear of the trans, like maybe the pan gasket is leaking, but I've never touched a bolt on that pan to break the bond on the gasket.
Fluid is all over the cross member holding the rear of the trans, down onto the rear part of the pan & some of the lower parts of the trans housing. I guess it is getting on that part from the air flow blowing it there.
Now the very rear part of the trans housing, tail end where the parking brake is located, drum & all is dry as a bone, no fluid on it at all on any of that part, so its not like a rear seal leaking.
Once under the M/H looking, its hard to see, because the cross member is in the way hiding the rear of the trans.

Anybody have a clue or if it has happened to them.
Thanks, Neil

CybrFalcon · 06-01-2012, 10:11 AM

I would bet that your parking brake unit is leaking. It uses brake fluid as lube and it's quite common for it to start leaking. Don't let it run dry.

Mekanic · 06-01-2012, 10:24 AM

Quote:

Originally Posted by CybrFalcon

I would bet that your parking brake unit is leaking. It uses brake fluid as lube and it's quite common for it to start leaking. Don't let it run dry.

Brake fluid?!?!? I think you mean ATF.
Brake fluid is ONLY used in the master cylinder of hyd brakes NOwhere else.

suppok · 06-01-2012, 06:43 PM

My 2000 Dutch Star (F-53) is doing the same thing very minor quantity, one or two drops in the course of a month on the concrete below trans. Pan is damp and cross member damp and sometimes slightly wet. I am pretty meticulous and cannot find source either. I am certain it is not park brake. I too have installed temp sensor in test port and have also drained and replaced fluid from the drain plug and converter drain.
John

C-Leigh Racing · 06-02-2012, 10:15 AM

Quote:

Originally Posted by suppok

My 2000 Dutch Star (F-53) is doing the same thing very minor quantity, one or two drops in the course of a month on the concrete below trans. Pan is damp and cross member damp and sometimes slightly wet. I am pretty meticulous and cannot find source either. I am certain it is not park brake. I too have installed temp sensor in test port and have also drained and replaced fluid from the drain plug and converter drain.
John

Wonder if it could have something to do, with installing the temp sending unit in that port hole on the side.

The plug that was in the port hole, looks like just about like a sending unit on the end, but is much shorter than the sending unit.

On yours suppok, did you have to cut the pull tie holding that wire & vent tube loose on the side of that bracket, so you could get to the plug in the hole.
When I did mine, I forgot to tie that hose back up & just left that vent hose hanging & was kind of thinking maybe air blew back up into the hose & pressured to transmission causing it to leak.
My plans today are, to pull that vent hose off & make sure its not stopped up & causing pressure to build inside the transmission.

Falcon,
Theres no oil on the rear part of the trans, where that part brake is located & from my understanding, the rear seal will go out & cause that leak, so if that what it was, theres no oil in that area to lead me to believe that is the problem.

Its the craziest thing, someone had just posted about getting the fluid changed on their 4 R100 & now they have found a leak & never one before. I guess a rash of transmission leaks are going to start popping up now. Does it ever end, like having something to do every time you turn around

.
Neil

suppok · 06-02-2012, 09:37 PM

I don't remember if I had to cut the wire tie or not. I had the dog house off today for another job and saw that there is a wire tie holding the vent tube in place, so if i cut it( and probably did) I replaced it. As I said earlier I tend to be pretty meticulous and do not like having anything loose or flapping so I'm sure any cut ties were replaced. I have also tightened the sensor to insure it isn't leaking. The source is mysterious. Perhaps coming from one of the shifter shaft seals. For now I just go under it and wipe things down periodically.

CybrFalcon · 06-04-2012, 12:06 PM

Quote:

Originally Posted by Mekanic

Brake fluid?!?!? I think you mean ATF.
Brake fluid is ONLY used in the master cylinder of hyd brakes NOwhere else.

You're right. I meant ATF.

C-Leigh Racing · 06-04-2012, 06:22 PM

Had some time yesterday, Sunday, to crawl under & do some inspecting.
Several of the trans pan bolt heads, had good amounts of oil on them, like enough to drip, so I wiped that off & got to thinking, now why is it so much on the bolts & like not enough on the edge of the pan to drip.
The pan was wet, not super wet like the bolt head though.
The cross member was wet as well, with places ready to drip, so I got some rags & wiped that off real good.

In my thinking, if those bolt heads have enough on them to drip, the oil must be coming out from around the bolt, so I pulled a bolt out & sure enough it was wet under & on the threads.

When you look close at the pan, the holes in the pan & gasket, are quite a bit larger than the bolt threads, large enough you can see the flat machined gasket surface area on the transmission casting, so now I'm thinking the oil is coming out around the bolt head & then blowing every where else.

I pull every pan bolt out, one at a time, cleaned them with carb cleaner & up in the bolt hole & put a good blobbing coat of the Permatex high temp red silicone on the threads, enough to squish up into that cavity hole in the pan & gasket.
On one of the bolts, once back in, I could see the red silicone had squished out between the top of the gasket & transmission casting, so that was telling me the gasket was not stuck to the transmission at that one bolt.

I've not ran the engine any, yesterday or today, allowing the silicone to cure out before hand & maybe seal those holes up, but if that dont fix it, I guess a new pan gasket is in order next with some good sealant on the gasket to be sure it dont leak.
Neil

Fiesta48 · 06-05-2012, 07:10 AM

My 4R100 was leaking at the parking brake. Pulled the plug to check the level. It was overfull. Drain it until it stopped running out. No more rear transmission leak.

garym114 · 06-05-2012, 07:47 AM

Why install another filter?
Will that reduce the flow through the coolers and change the pressures as it loads up?

BFlinn181 · 06-05-2012, 09:03 AM

I hope you found your leak, but be aware that since bolt heads are the lowest point, oil often migrates to those points to gather and form drips. Sometimes the leak is far from that point. To find, the surface must be cleaned, not just wiped, and then frequently inspected to determine leak source.

Remember your RV is just like old air cooled VWs, they don't leak, they're just marking their territory!

Arch Hoagland · 06-05-2012, 09:11 AM

Quote:

Originally Posted by garym114

Why install another filter?
Will that reduce the flow through the coolers and change the pressures as it loads up?

That's what I'm thinking too.

C-Leigh Racing · 06-05-2012, 01:04 PM

Quote:

Originally Posted by garym114

Why install another filter?
Will that reduce the flow through the coolers and change the pressures as it loads up?

Ok, let me ask you this then, does the 4R100 have a filter inside or just a fine screen.
Seems like I read somewhere, the 4R100 didnt have a filter inside, which to me would seem mighty crazy not to have one.
Neil

C-Leigh Racing · 06-12-2012, 11:15 AM

"Update"

Found the trans oil leak.
Big dummy that put the temp sender unit in the test port, forgot to remember, HE, never put any teflon tape on the threads or tightened the sender up completely, I could kick my stupid self.

Got ready to pull out last Wed, 6/6 for OK trip & wouldnt you know it, trans fluid dripping, so I jack the front up & crawl under while engines running & a slite stream was running from around the threads of the sender.
Every time I've checked it out, the engine was never running, so never seen the oil running out, so that was my problem.

Around a 2400 mile trip out to OK & back & ol trans pan is clean & dry as a bone, no oil leak.
Neil