• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Tire pump in reverse?

Share this page

NutmegCT

NutmegCT

Great Pumpkin
Bronze
Offline
For at least ten years my B&D 500 amp battery replacer with tire pump has worked without problem.

Yesterday my Altima "tire system" said all four tires were low. I checked with my usual gauge, and they were all 25 or 26, supposed to be 33. Pressure had dropped due to sudden cold snap.

I used the tire pump and raised three of them to 32psi; right front wouldn't increase - weird. I checked the pump, and despite sounding normal, there was no air coming from the hose. Maybe trying to do all four tires had somehow "killed" the pump? I tested the spare, which showed 30psi. I used the tire pump and after about two minutes, the pressure had *dropped* five pounds.

Opened up the case, examined all the lines, wires, hose, battery, pump, etc. Battery was 12v as usual. I couldn't see problems anywhere.

What would cause a tire pump (electric, vibrator type) to fail? Motor/vibrator seems fine, but no pressure.

Thanks.
Tom M.
 
Age. Sitting long spells. Nothing new will last that long. I had a craftsman air compressor that when I was draining it I felt air. Found a hole from internal rust, lasted 40+ yrs. Betting my new upright won't make it after warranty over or local repairman retires.
 
Thanks Larry. Guess I'll keep it for the battery jump start feature (which I've used many times). Was strange to see the tire pressure drop when I thought I was increasing the pressure. Ya can't win!

T.
 
Don't make stuff like they used to. Don't make people like they used to either!
 
I do not know design details of these pumps, so please take what I say with a huge grain of salt:

I’d assume it is a pancake compressor. Meaning a motor pushes on a diaphragm, and a one-way valve makes sure air goes forward.

If the diaphragm has a tear, or the one-way valve goes kaputt, then the unit will make noise, but not move air.

Alternately, the valve to the tire could have a bad seal (meaning the end of the pump hose, not the tire stem). In that case the air gets pumped in the right direction, but leaks to atmosphere instead of into the tire - along with air in the tire.

And for my final assumption, parts might be hard to get, if at all. You could “upgrade” to a Porter Cable pancake compressor, which is bigger and 120V, but may have better parts support.

Good luck!
 
Thanks Mike. I think it's the "bad diaphragm" problem. There's no air pressure coming from the end of the hose at any time, when pressed onto any other tire valve, even my spare. So when I tried the pump, the tire "exhausted" its contents and lowered its own pressure.

All I want for Christmas is a good tire pump, a good tire pump, just a good tire pump!
 
Back
Top