Converting Tyre Pump to Vacuum Pump

Introduction
Want a vacuum pump? Have you ever think about converting the cheap tyre pump into vacuum pump? Here is how.

What is the use of Vacuum Pump?
One can use the vacuum pump for
1. Vacuum Sealing of food for packing and preservation;
2. Vacuum pressing of materials under atmospheric pressure; example, press sealing of veneer to a piece of plywood;
3. Vacuum replacement of car motor oil without carrying out undercarriage oil draining

What One will Need ?
1. A 12-volts electrical tyre pump
2. A short length of pressure hose
3. A hose clip
4. Some Epoxy glue

The 12-Volts Tyre Pump
One can find the cheap 12-volts electrical tyre pump in practically every store. They are small but yet powerful to inflate tyres. Some of them are capable of delivering more than 200 psi of pressure.

They are never designed to be vacuum pump but the piston construction of which make them candidates for conversion into vacuum pumps.

Find a tyre pump that has suction hole as shown attached. There are some that do not have these features.

The Construction of the Pump
The Tyre pump consists of 4 components
a) The 12 volts electric motor
b) The gearbox
c) The piston
d) The discharge and suction valve

The Conversion Work1. Cut a piece of tube of about 40 mm long;
2. Carefully insert the tube just to cover the suction holes of the compressor;
3. Use small amount of quick dry cement to secure the tube in place first, then use high temperature epoxy glue or just ordinary or steel epoxy glue to fill the gap and build the mount to secure the tube. If necessary, reinforce the tube by tying the tube to an attachment of the pump and fill them all up with the epoxy glue.
4. Insert the hose and clip after the the glue is dried. Reassembled the cover in place.

Limitations1. The pump is not designed for prolonged operation. Operation of more than 20 minutes might seize the piston as excessive heat would build up;
2. The pump can only pull a vacuum of about 20 to 25 inches of mercury. Not necessary suited for use in car air-conditioning repair work;
3, It draws about 4 amperes of current from a 12-volt DC source.