leaking engine driven fuel pump

[Wallbangar]

MAYDAY...MAYDAY...MAYDAY

Have RV-7 with Mattituck O-360 Carburated. Went to change oil yesterday and found fuel spot under cowling. De-cowled and found fuel leaking from E.D. Fuel Pump. Discovered all six 1 1/2" bolts holding the diaphram up onto the pump were finger (not)tight with fuel leaking out of the circumference. Tightened all six with screw-driver & of course stripped one of them. (Very soft metal). Called Mattituck and was told that was the first problem they have had with same. No other problems in 340 hours of heavy flying. Don't know if vibration backed them off or they were that way from the start. Suggest you check yours ASAP. Might save a walk back to the hangar.
p.s.----They didn't make the pump.

[mahlon_r]

That is a very serious problem. I suggest that you contact the local FAA office and tell them you want to make a " Malfunction and defect report" or go to http://av-info.faa.gov/isdr/LongForm...32&vF=LongForm and fill it out.
If anyone else has the same problem it will get pooled in the data base. This is the system the FAA can use to make AD notes and if this happens to others it should be an AD note in my opinion.
Good Luck,
Mahlon

We just had the samething on a IO-540 from penn-yan and believe it or not the only reason I checked it was because our fuel press. was so low on take off. Now before any of the critics get on here and say why didn't you have your boost pump on for take-off, its one of the tests I run on a long runway.

[Geico266]

Is there safety wire holes in the screws? I have not looked at it, but it seems to me this would be a good place for safety wire & loctite.

No, on the penn motor it had the spring circle under the screws.

[Wallbangar]

Just received new pump from Mattituck that has lock washers under all six bolts with torque seal on two of them. OLD ONE HAD NOTHING ON THEM ! ! ! -------Must have been made in CHINA !!!!!!!!!!!!!!!!

[Indiana Larry]

Have RV-7 with Mattituck O-360 Carburated also. I have about 550 hours on the engine and recently noticed my engine monitor warning of low fuel pressure. I checked the fuel pump and found the bottom screws almost less than finger tight. Tightened all to 25 in.lbs. and at engine run the fuel pressure was 8 psi ( a bit high but it was ok with me at the time.)

After another 8-9 hours of flying, at take off without the auxiliary fuel pump on, the engine stumbled making less that full power. Carb heat did not clear it but applying auxiliary fuel pump did restore full power and pressure to 6 psi. Now without auxiliary pump power on, fuel pressure is less than 1 and falls below my expectation of 4-6 psi. I have filed, as suggested by Russell Mahlon of Mattituck, the Malfunction and Defect Report with the FAA.

My engine was built about 10 years ago and I will order and install a new Tempest pump in a few days. Over the years of good engine performance, I admit I became complacent and did not check closely the condition of the fuel pump screws at annual. As my experience tells, the fuel pump is important so I am putting that check of the screws on my annual condition check list.

Thanks to all for info on this forum.

[Ron Lee]

Originally Posted by Indiana Larry

Now without auxiliary pump power on, fuel pressure is less than 1 and falls below my expectation of 4-6 psi. I have filed, as suggested by Russell Mahlon of Mattituck, the Malfunction and Defect Report with the FAA.

This is very common. I have beaucoup hours and see less than 1 psi often. The engine has yet to stop running except when I ran a tank dry.

Obviously you should investigate to rule out any true fuel system problem(s).

[Vlad]

Had screws loose on engine driven fuel pump after 200 hours. Stock carbureted Lycoming. Now checking every 100 hours.

[BSwayze]

Originally Posted by Vlad

Had screws loose on engine driven fuel pump after 200 hours. Stock carbureted Lycoming. Now checking every 100 hours.

Vlad,

Wouldn't it be even better to get bolts with holes through the heads and safety them?