Oil & Fuel 4500 Fuel Tank Vacumn Buildup

[Clyde]

I bought my Mahindra 4500, 4wd, w/FEL last September. I really didn't have a chance to use it thru the winter months for any length of time per use but I am starting to use it now with a new Wood's 720 brush mower. Here's the problem....After working the tractor for approx 3 hrs under load, the tractor started to sputter and lose power. The fuel gauge showed 3/4 tank full yet but I shut the tractor down and tried to open the filler cap on the fuel tank to make sure I wasn't running low on fuel in case the gauge was faulty. It was a chore just to loosen the cap and then I couldn't even have pried the cap off if I tried. I kept trying to lift the cap off and heard a slight hiss of not pressure but vacumn. It took me a full minute to finally relieve the vacumn and took the cap off. The gauge was right and I still had fuel 6" down. I put it all back to normal and restarted the tractor and all was great. I mowed for another hour without problems and returned the tractor to the shed. I checked the tank once again and vacumn was once again building up.

I called Mahindra Tech Support and now I know how it must feel to go to a psychiatrist. Essentially - you solve your own problems or just live with it.

 

[Bird]

Clyde, it seems as if that should be a simple problem to solve. I'm not familiar with that model, but does it have a vented cap? If so, the vent is obviously stopped up. If it's not a vented cap, then the fuel tank itself should have a vent; perhaps an overflow tube, as some have. If it has an overflow tube instead of a vented cap, then I'd be looking at the tube to see if it's pinched somewhere.

 

[Clyde]

Bird - the vent is supposed to be vented according to Mahindra. There are two slots molded inside of the plastic cap that follow thru to the center of the cap. As I see it, the only blockage to this airflow is the rubber gasket that appears in most instances to prevent spillage. The blockage would appear when the rubber gasket is compressed into these slots when the cap is properly tightened. If left too loose, then I get sloshing of the fuel and the inevitable fuel spillage to the outside of the tank. I think it is of poor design and engineering. Yes - I could drill a small hole in the top center of the cap but then with no filter I am pulling in dust to my fuel system. I like my 4500 and it was a good dollar value but oversights like this and no decent support or interest from Mahindra on solving the problem leaves me to solve my own problems it appears. I appreciate any and all ideas on this guys

 

[BobG_in_VA]

Here's the simple answer: I had the same problem with the fuel tank venting, except I never had the engine die from it. I noticed early on that when first starting the tractor it could take the engine about 5 revolutions in turnover till it fired and started. All was well after that. I noticed the vacumn when refueling one day. I ultimately surmissed that the vacum in the tank was actually keeping the fuel from flowing to the pump and thus taking more revs to start than it should. Once you have taken then cap off a number of times (10 or so you will notice that the vacumn will become less and less. I now do not notice any variance on starting cold but when refueling I still get a slight amount of "pull" on the cap. When you get ready to shut down for the night, vent the tank (take of the cap) and replace it. You will be ready to roll in the AM. BobG in VA

 

[dieseldoc]

hey clyde,i bought a 4500 in jan.i haven't had a problem with a vacumn buildup but after reading your post i will keep an eye on it.

 

[Poboy]

You might go to your dealer and try a new cap because they have had a very small amount of defective fuel caps. The caps did not vent properly. We have sold a lot of these tractors but we have not had any problems with this.

 

[johnsonauto]

It sounds like you have a bad cap/vent, have you tried your dealer? They should be able to help you. I have not had this problem as of yet on any of our "00" series of yet that we have sold. But i called my Tech rep for my area, which also covers your area and he said there were a few that had caps machined wrong and did not vent, a new cap is availible and everyone at mahindra should be aware of it. So he was a little shocked when i told him you got no answers from there tech people. I'll send you a private message with the tech's cell phone number. He said give him a call if you need too.
If i can further help you feel free to call me toll free 1-866-393-0642.

Scott Johnson

www.NewEnglandTractor.com

 

[Clyde]

Thanks to Johnsonauto and his contacts with Mahindra, we were able to ascertain that indeed there were some defective fuel caps out there and not specific to the "00" series. The beauty of this forum is that there a vast cross section of talents and dedicated owners of Mahindra tractors that I believe any problem and a solution to any problem is possible. I'll let you know if the replacemnt cap fixed the problem.

 

[Clyde]

Once I contacted the dealer I bought it from and ordered a new cap, it took 3 days to receive a new cap sent right to my address. Maybe I should take time to let you all know that the closest dealer to me at the time I bought my tractor was 210 miles away(one-way). I was impressed by the Mahindra 4500 4wd and I knew I was taking a chance on this purchase as far as product, dealer, and reliability of the product. I purchased the tractor from Burright Welding and Equipment out of Mt Morris, IL and he delivered it for no extra charge. Anyway, the new cap works perfectly. I took apart the old cap and the new cap to compare any differences and definitely the old cap never could have worked. Mahindra uses the same cap for most of their machines and more that just the 4500 series could have the defective cap. Obviously, there aren't that many defective ones out there gauging by the lack of posts describing this problem. Thanks to all for their input in helping to solve my problem.

 

[johnsonauto]

Glad to hear it all worked out for you. Good luck, if i can be any further help feel free to contact me.

Scott