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Gear pump won't prime so customer trys to plug bypass with grease

Gear pump won't prime so customer trys to plug bypass with grease

Gear pump won't prime so customer trys to plug bypass with grease

(OP)
Customer used this pump for several months, then one day says it wouldn't prime. The internal bypass for this pump has an adjustable set screw that seats a ball/spring combination. They took out the fittings in the bypass, jammed in a grease zerk and cracked the housing (probably because the grease fitting had different threads). Has anyone heard of using grease to plug a pump so it primes? From a common sense standpoint that seems asinine to me, the grease could migrate out of the bypass and gum up the rest of the pump over time right?

RE: Gear pump won't prime so customer trys to plug bypass with grease

Probably thinking that the grease would seal the pump gear clearances so the pump would move air and therefore draw and prime the pump.

Ted

RE: Gear pump won't prime so customer trys to plug bypass with grease

Hydtools makes sense as to the reason to try grease. The crack is almost certainly due to applying too much pressure with the grease. Grease guns can apply many thousands of psi. Perhaps the zerk fitting was applied to the wrong end of the pressure bypass and could not open the ball check.

RE: Gear pump won't prime so customer trys to plug bypass with grease

It looks like a cheap Chinese rip-off copy of a simple pump.
The analysis time is greater than the cost of a new pump.
The pump cover has been taken off several times, judging by the screwed up paint and scars on the faceplate bolts.
Open it up again, and see if any grease actually got inside.

RE: Gear pump won't prime so customer trys to plug bypass with grease

Older pump that operated 99% of the time in bypass, and erosion/cavitation destroyed the ball seat. Enough that even full travel on the ball wouldn't prevent leakage during priming. So, a desperate move to seal the bypass channel "temporarily" with a grease plug.

RE: Gear pump won't prime so customer trys to plug bypass with grease

Not exactly the same, but in days of yore it was not uncommon to assemble a Chevy V8's oil pump with Vaseline to enhance the first prime.

It was even in the Buick factory shop manual for some years.
http://www.oldcarblog.com/manuals/1963/Chassis%20M...

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