pump maintenance

Do you remember how nice it was when you first got your pump? You would pump it up to pressure and you could pretty much leave it there for the length of the pump cycle without adjusting the pressure. Now as you have put some time on the pump you find you have to adjust the pressure to keep it up where you want. I found this to be the case with my plunger style pump. I kept checking the seal around the base of the tube but it wasn’t that. Then I noticed that the plunger was “dragging” against the inner wall of the plunger tube instead of a nice smooth sliding motion. To fix this problem just take a little bit of olive or vegetable oil and pour it into the suction end of the pluger tube then draw the oil through the tube by pumping until it feels smooth and slides easily. This is some basic maintenance that should be done once a week to keep these plunger style pumps in shape. DO NOT USE MOTOR OIL OR ANY KIND OF PETROLEUM BASED LUBRICANT….. this will break down the composition of the rubber seals in the plunger tube and ruin them over time. You should be using enough oil so that as you pump it through the plunger tube it spurts out the other end, just keep pumping it through until the spurting stops. I’m sure you MityVac owners could also use this method of maintenance as well.

Is this not going to hurt a gauge? Or maybe I am understanding something wrong.

~Q

My pump doesn’t have a guage so I dont have to worry about damage to the guage. It is my understanding that the majority of plunger style pumps don’t have a guage. If your Mity Vac is the plastic one, I have read several times that you can wet pump with it. I suppose that you could try drawing water or oil through to see if it gets up into the guage or you should be able to disassemble the pump body and just lube up the plunger. What I suggested in the opening thread was primarily for plunger style pump maintenance. I remember reading a post somewhere in the past that said you can lube the plunger in a MityVac so you should still be able to perform this type of maintenance on it. Of course what you do is at your own risk and ultimately your decision, I was only sharing a solution that I came up with for standard “bilge” style plunger pumps.

No I hold you completely responsible, noone else, just you. I have no say in my decision making process. :)

Just kidding. I have a pump from Welcome to lapdist.com the deluxe edition with the guage.

I just wanted to let people know that not all of these pumps can have this done. Atleast to the best of my very limited knowledge of them.

~Q

Thanks Quest, but you know if I didn’t put that disclaimer up some fool would try to blame me,and its just as well too. I’m glad you posted back to bring this issue to light, otherwise I’d be swimmin’ in shit! Thanks for helping me cover my ass Bro!

Use veg-able oil best lube for the rubber in the pump. My plastic pump has been used for years, and still works fine.

You can always add a water trap to it like in the brake bleeding kits.

I just lubed my quick connect parts tonight with macadamia nut oil (I couldn’t find the olive oil) still didn’t fix the problem. I hate having to screw and unscrew the pump because the spring takes a lot of fighting to wrestle down. I have tried different lubes in the past I don’t recommend any petroleum products for the reasons listed above or water based lubes because they gunk up.

You do know you are answering a thread that hasn’t been active for six years, don’t you?