Leak from underneath chassis - not sure what these lines are

[Lette]

I have had this leak coming from these dual lines that I'm just not sure what it is? its a 2016 Winnebago Vista 31be with 20K mileage. When you look underneath it is the 2 lines on the left side underneath. Ive researched and for some reason don't have details on the F53 chassis. Any guidance is greatly appreciated....see pictures...hopefully I did it right...:-)

[BobC]

I know nothing about F53s, and I could be 100% wrong, but they appear to be air conditioning lines. Are you sure it's a leak and not condensation? Is it water or some other fluid? Here's a link to some A/C lines for a Ford F250 for comparison:

https://www.partsgeek.com/qqbbw3h-fo...saAiFfEALw_wcB

Maybe you can find out something here: https://www.google.com/search?q=ford...6s5a0eMaFtlE3M

If they're A/C lines, they should be easy to follow back to the compressor and, if it's water, it's likely to be condensate and not a problem.

[Ray,IN]

Ford F53 automatic transmission cooler as discussed here: https://www.irv2.com/forums/f23/f53-...ak-441121.html



A side note, most people think the A/T lines into/out of the bottom of the radiator are cooling lines, they are not. They are for heating A/T oil up to normal operating temperature quicker for better transmission performance.

[BobC]

I guess I was 100% wrong. Oh well.

[Lette]

Hi Bob, your thought brought me right to the cooling section and I found the info Ray mentions above! So no worries!

[Lette]

Hi Ray, thank you! I found that very link last night too! Next question, where can I fill it up once I have the fluid. I'll double check my manual but I don't recall any location for "Transmission Cooling Oil"....

[Ray,IN]

Originally Posted by Lette

Hi Ray, thank you! I found that very link last night too! Next question, where can I fill it up once I have the fluid. I'll double check my manual but I don't recall any location for "Transmission Cooling Oil"....

Incredibly, transmission mfgrs. expect us to add ATF via the dipstick tube. That is the only way. Start shopping for the right funnel to fit your space.
That is doable for gas chassis, but my DP has the dipstick tube horizontal the last foot.

[BobC]

Don't you have to fix the leak before filling or are you filling to determine the source of the leak?

[bigb]

Be careful, transmission fluid is not something you just fill up like your coolant reservoir, it has to be carefully checked while at operating temperature with the engine running while parked on a level surface. Multiple checks and wipes of the dipstick are often necessary to verify the level as it smears on one side of the stick and is also hard to see when clean (as it should be) as it is nearly clear. I usually roll the dipstick over on a clean blue paper towel which reveals the wet area. One side will be lower, that is the level.
Also, transmission fluid spreads out a lot so a small leak can look like a lot bigger of a leak than it actually is so don't be surprised if it still shows full when you check it.

[Lette]

Originally Posted by BobC

Don't you have to fix the leak before filling or are you filling to determine the source of the leak?

Hi Bob, I know where the leak is coming from for sure and it is identified above. The lines for the transmission cooling. Its where it is coupled. So new lines need to be ordered. I will have someone replace it. Hopefully, the design was improved....

[Lette]

Hi BigB, agree. After further investigation and reading the manual I know I have to heat up the vehicle then check and fill accordingly. It is a process that you need to wipe the stick, and reinsert about 3 -4 times before determining where you are at...+level the vehicle..... I was in the "ADD" section of the stick. I put 1 1/2 qts in. So it is not a terrible leak HOWEVER, who wants to lose a transmission because of a poor design....I only have 20K on this rig ford! I see it takes 17.2qts. But low is low.....

Thank you all for identifying this...next is to repair this puppy!!

[bigb]

Originally Posted by Lette

Hi BigB, agree. After further investigation and reading the manual I know I have to heat up the vehicle then check and fill accordingly. It is a process that you need to wipe the stick, and reinsert about 3 -4 times before determining where you are at...+level the vehicle..... I was in the "ADD" section of the stick. I put 1 1/2 qts in. So it is not a terrible leak HOWEVER, who wants to lose a transmission because of a poor design....I only have 20K on this rig ford! I see it takes 17.2qts. But low is low.....

Thank you all for identifying this...next is to repair this puppy!!

Actually 1.5 qts is a very substantial leak for an automatic transmission, it must be leaking pretty bad or for a very long time.

[Lette]

Originally Posted by bigb

Be careful, transmission fluid is not something you just fill up like your coolant reservoir, it has to be carefully checked while at operating temperature with the engine running while parked on a level surface. Multiple checks and wipes of the dipstick are often necessary to verify the level as it smears on one side of the stick and is also hard to see when clean (as it should be) as it is nearly clear. I usually roll the dipstick over on a clean blue paper towel which reveals the wet area. One side will be lower, that is the level.
Also, transmission fluid spreads out a lot so a small leak can look like a lot bigger of a leak than it actually is so don't be surprised if it still shows full when you check it.

Originally Posted by bigb

Actually 1.5 qts is a very substantial leak for an automatic transmission, it must be leaking pretty bad or for a very long time.

Yes, it has been a while. I just purchased some more Motorcraft MERCON LV qts and will be checking until the part is ordered and replaced.

Thanks again!!