Air pump fits on front tire valve, but not on rear. won't catch valve stem...both are schrader valves. help???

The valve stem itself can only be changed after taking a least one side of the tire off/away from the rim.
The schrader valve which is the little stem inside the valve stem is changed which a special inexpensive tool.
The valve stem and schrader valve are both available at any auto parts store. They can help with any other questions too.

On the Mark VII, they came with an emergency fill schrader(like a tire valve) valve on the compressor head. To use this, simply apply compressed air to the Schrader valve WHILE THE PUMP IS RUNNING. The reason I say while the pump is on, is because if the compressor is on, the solenoids on the front or rear WILL be open, thus allowing air into the air spring(bag).

Nothing is wrong, it's just a different kind of valve called a presta valve instead of the more common schrader valve. Just stop by the bike shop and ask them to pump it up for you or if you want, to adapt the rim to fit a schrader valve. If you do that have them put in the new inner tube.

This pump is a bit strange to use. The valve in the filler head is odd in that it controls the flow of air in both direction...which is not a great design in my opinion...but it does allow for use in different filling applications. The trick is getting the pump into its different filling "modes"

For a Schrader bike valve:
1. Make sure the pump is in "tire mode" by blowing into the valve with your mouth. If you then pump the handle you should feel air filling your mouth.
2. Put the "locking lever" in the unlocked position, the unlocked position is when the silver metal lever is parallel to the air hose, or said another way it makes an "L" with the air outlet that goes on the tire air filling stem. To verify this is correct, look in the air outlet and move the lever from locked to un-locked, you will see slight change in the diameter of the outlet.
3. Push the air filler hole over the schrader valve really hard and make sure it is seated all the way down. Close the "locking lever" (silver metal lever should now be perpendicular to the air house and be in line with the air outlet... i.e. point straight out away from the tire filler stem.
4. Pump.

For a Presta bike valve:
1. Make sure the pump is in "tire mode" again.
2. Take off plastic caps off presta valves on bike tire.
3. Unscrew the little nut on the presta stem to allow the tire valve to open when pressure is applied (you can test this by pushing the stem in a little and air should escape, the nut holds the valve closed, so it needs to be loosened).
4. Take the adapter from the locking lever (silver metal lever) on the pump and screw it on the presta valve. The adapter is the brass looking thing. Screw the rubber gasketed side down on the presta valve.
5. Press the air pump tire filler outlet onto the adapter.
6. Close the locking lever to seal the filler head on the adapter.
7. Pump.
8. Unlock the locking lever and pull it off quickly.
9. Unscrew the presta adapter and screw down the presta valve nut but just finger tight.
10. Screw on the plastic cover cap for the presta valve.

To Fill a Ball:
1. Twist the ball pin filler out by rotating the gray plastic tab around until the ball pin filler is pointing straight out (in-line with the air hose).
2. Make sure the pump is in "Ball mode" by again blowing into the filler. Sometimes shaking the filler valve really hard is necessary.
3. Put the filler pin into a ball.
4. Pump.

Hope this helps.

Download this from Blackburn. It will give you an idea how it all fits together even if it's not a Blackburn pump.

http://www.blackburndesign.com/manuals/Mammoth_Airstik_MAP.pdf

Not all pumps come ready for schrader. Maybe you have to reverse the head parts.

There are two types of valve stems, schrader ( like the valve stems on your car ) and presta. See images on this page http://www.sheldonbrown.com/brandt/presta-schrader.html Since you are asking I assume you have presta valves. You can get an adapter to convert the presta valves for use with a schrader pump. Unscrew the small knurled nut on top of the presta valve to open it, press down and release the small top to ensure the valve is free to move. Snug up the top when it is full.

What's different?

http://www.youtube.com/watch?v=Ehf6HL0aLTc

http://www.ehow.com/how_4779541_inflate-bicycle-tire-presta-valve.html

1. Rotate the wheel so the valve is resting just above the floor. Remove the valve cap.
   

2. Unscrew the locking nut on the valve stem. Quickly press down the stem to loosen the seal. You should hear air escaping when the stem is pushed in--if you do not, loosen the nut and try again.
3. Press the pump head onto the valve and flip the locking lever to make a seal. You'll hear air escape, but it should stop after you've locked the lever. If air continues to leak out, remove the pump head and reattach it.
4. Make two pump strokes and listen for air moving into the tire. If the pump handle becomes hard to press down after only a few strokes, or if the pressure gauge elevates extremely quickly, remove the pump head and repeat Step 3.
5. Inflate the tire to its recommended pressure. Remove the head by unlocking its lever and quickly pulling it off the valve stem. Secure the valve's locking nut and cap.

Read more: How to Inflate a Bicycle Tire With a Presta Valve ' eHow.com http://www.ehow.com/how_4779541_inflate-bicycle-tire-presta-valve.html#ixzz1Brv5VfAX

There is a schrader valve on the fuel line on the engine for attaching a fuel gauge to monitor the fuel pump for testing purposes, and it should have a cap on the valve similar to a valve stem cap on a tire. (relieving the fuel pressure is similar to letting the air out of a tire and watch out for any fuel spray) or you can loosen up a line fitting at the fuel filter until the pressure bleeds off then replace the fuel filter, and you might want to have a pan to catch the fuel in, and be very certain that there is no ignition source anywhere near the vehicle.

Your bike tube has Presta style valves. Automotive style valves are known a schraders. To inflate the tube, you will need either an adapter, presta to schrader or a hand pump that has a head for presta valves. Any bike shop will have one for sale. To fill the presta valve style, remove the black cap(if it is there) You will see little stem with a small knurled nut. Screw the nut all the way up until it stops. Put the pump head over the stem, making sure it is pushed down. Flip up the lever on the pump head, fill to desired pressure 100 to 120psi...yes, that much pressure, it's a road bike. Flip the lever on the pump head down and remove it from the stem. The PSST you will hear is the air from the line on the pump...not the tire. Screws the knurled nut down and replace the black cap. If you do not srew the little nut down and push on the stem you will let the air out of the tire. If you need more help, you can email me @ [email protected] and I will send you pictures of the process, or the staff at your local bike shop should be able to show you how.

if you open up the hood and find your fuel rail you should see a little cap just like what is on your tire valve stems. take the cap off and push the little valve in the center agian just like the valve stem on your tire. be vary carefull as fuel will spray out of this. that is how to depressurize the fuel system