hydraulic pump piston issues

willowbk · Jan 31, 2015

Hey guys, in the process of starting to restore an f40. When I drained the oil out I found part of the piston pump in the bottom. So I removed pump, completely disassembled and got 2 new pistons w/ updated ring set up. My question is I have it all back together and there seems to be a lot of play on the rear piston(left and right wobble). It travels about an 1/8th of an inch. The front piston doesn't travel nearly as much. In the picture it is the one with the blue tape on it. Any thoughts or input would be appreciated.

DavidP, South Wales · Feb 1, 2015

Hi, is the pump tight to turn? The problem that you appear to have is that at least one of the pistons is fitted the wrong way round. The pistons on the blocks might appear to be in the centre but they are not. This can be seen in your photo. The distance from the piston centreline of the front one is greater than to the rear face of it. Strip the pump and turn the block around. That way the phosphor bronze inner block face will be completely covered and you will have space between the block and front plate of the pump. Ensure that the oscillator ring (magnifying glass shaped piece) is completely free when the pump is fully assembled.
DavidP, South Wales

hydraulic pump piston issues

willowbk

Member

DavidP, South Wales

Well-known Member

Similar threads