tire electric pump recommendation (Shell beach tire deflation)

Just wait!

Here is my post for July 3, 2016, in the Nomad Off Roading forum:

One of the most important items to have in your Baja bound vehicle is an air pump to reinflate tires. Deflating tires off the pavement is key to both puncture resistance and traction/ flotation.

Another use for the air pump is to refill a flat tire after you plug a hole (if you didn't deflate before off pavement driving). So, have a tire plug kit, as well!

I have had three models of electric tire pumps over the past 35 or so years.
I started with one that plugged into the cigarette lighter... It was not so bad because at the time, my 4x4 was a Subaru with 13" tires, and I would just wait the time it took to refill.

When I started off roading in a Tacoma, with 16" x 31" or 32" tires (265/70 or 75 x 16) the cigarette lighter powered unit was just too slow, adding air at the rate of 2 psi per minute. That meant to go from 15 psi to 35 psi (20 psi added) would take 10 minutes per tire or 40 minutes for all four.

The great aridologist, Mr. Neal Johns, recommended the General Pneumatic brand pump with a power cable that clips directly onto the battery... was on sale for $49.95 at Harbor Freight. That unit filled my tires at the rate of 6 psi per minute, three times faster (3.3 minutes/tire).

On the negative side, the power cable gets very hot and the fuses would melt (not blow, but the plastic housing would melt). The large hard plastic carrying case was a bit bulky, too.

I acquired an MV-50 SuperFlow pump and it was perhaps a tad slower but the wires did not overheat and it fit into a smaller, canvas carrying case. It gave me years of good service until my last use, last year, just south of Gonzaga Bay, when I was refilling my tires and when moving the fill hose to reach the last tire, accidently P-nched the tube (while the pump was running)... and that blew out an internal check valve and ended its life!

That was not the pump's fault! But, TURN OFF the pump between tires, just in case!

Well, for Father's Day, my kids got me a new MV-50 along with some of those automatic deflator devices you screw onto the tire stems. I did an in garage test, using a stop watch... Here are my findings:

Using a precision dial pressure gauge, I deflated my tire to 20 psi then timed how long to add 15 psi (back to 35 psi). The answer was 2.5 minutes for a 265/75-16 all terrain tire.
1 min = 6 psi ADDED
2 min = 12 psi
3 min = 18 psi
4 min = 24 psi
5 min = 30 psi

The gauge on the pump was pretty accurate when the pump was not running, but jumps almost 10 psi when on and filling. So, to know when to remove the fill hose, I ran the pump until the gauge was just below the 45 psi line (for 35 psi in the tire. You can toggle the on off switch to see the more accurate pressure.


2 minutes???
In 2 minutes, it will add 12 psi to a truck tire, if the tire is flat, you may need closer to 6 minutes if your tire needs around 35 psi for the highway. Obviously more time if you have a higher pressure tire.

Quote: Originally posted by John M

Viair 400p - reliable and not inexpensive.

Quote: Originally posted by kevin_in_idaho

Wow... great info on the forum but now... If we want to camp at Percebú (Shell beach/island) and have to deflate our tires, I guess we should have a way to inflate the tires. What electric pump have people been using? I saw that someone got one at Harbor Freight and it wasn't so good. Do we have to really deflate our tires to get on the beach at Percebú or are there places we can reach w/o doing that? I guess it's good to have a pump either way (and patch/plug kit).

buy cheap, and buy it twice!

$15 air compressor should work at least two times before it overheats and dies

Quote: Originally posted by John M

Holy Smokes Kevin - just you wait - the flood gates will very soon open and you'll be deluged with a variety of quality and prices, adamant opinions, wild guesses, and the like. This is one of the hot topics that sparks reply after reply. So, my choice - Viair 400p - reliable and not inexpensive. John M [Edited on 1-19-2017 by John M]

Quote: Originally posted by David K

Here is my post for July 3, 2016, in the Nomad Off Roading forum: One of the most important items to have in your Baja bound vehicle is an air pump to reinflate tires. Deflating tires off the pavement is key to both puncture resistance and traction/ flotation. Another use for the air pump is to refill a flat tire after you plug a hole (if you didn't deflate before off pavement driving). So, have a tire plug kit, as well! I have had three models of electric tire pumps over the past 35 or so years. I started with one that plugged into the cigarette lighter... It was not so bad because at the time, my 4x4 was a Subaru with 13" tires, and I would just wait the time it took to refill. When I started off roading in a Tacoma, with 16" x 31" or 32" tires (265/70 or 75 x 16) the cigarette lighter powered unit was just too slow, adding air at the rate of 2 psi per minute. That meant to go from 15 psi to 35 psi (20 psi added) would take 10 minutes per tire or 40 minutes for all four. The great aridologist, Mr. Neal Johns, recommended the General Pneumatic brand pump with a power cable that clips directly onto the battery... was on sale for $49.95 at Harbor Freight. That unit filled my tires at the rate of 6 psi per minute, three times faster (3.3 minutes/tire). On the negative side, the power cable gets very hot and the fuses would melt (not blow, but the plastic housing would melt). The large hard plastic carrying case was a bit bulky, too. I acquired an MV-50 SuperFlow pump and it was perhaps a tad slower but the wires did not overheat and it fit into a smaller, canvas carrying case. It gave me years of good service until my last use, last year, just south of Gonzaga Bay, when I was refilling my tires and when moving the fill hose to reach the last tire, accidently P-nched the tube (while the pump was running)... and that blew out an internal check valve and ended its life! That was not the pump's fault! But, TURN OFF the pump between tires, just in case! Well, for Father's Day, my kids got me a new MV-50 along with some of those automatic deflator devices you screw onto the tire stems. I did an in garage test, using a stop watch... Here are my findings: Using a precision dial pressure gauge, I deflated my tire to 20 psi then timed how long to add 15 psi (back to 35 psi). The answer was 2.5 minutes for a 265/75-16 all terrain tire. 1 min = 6 psi ADDED 2 min = 12 psi 3 min = 18 psi 4 min = 24 psi 5 min = 30 psi The gauge on the pump was pretty accurate when the pump was not running, but jumps almost 10 psi when on and filling. So, to know when to remove the fill hose, I ran the pump until the gauge was just below the 45 psi line (for 35 psi in the tire. You can toggle the on off switch to see the more accurate pressure. 2 minutes??? In 2 minutes, it will add 12 psi to a truck tire, if the tire is flat, you may need closer to 6 minutes if your tire needs around 35 psi for the highway. Obviously more time if you have a higher pressure tire.

Quote: Originally posted by Maderita

I have a Viair 400P, portable, 33% duty cycle. Also a Viair 350C Continuous (100%) duty cycle, mounted inside a "fat 50" ammo can for portability. Great units. If you must rely on your compressed air system, it dosen't pay to go cheap. With regard to "Shell Island", I'm assuming that you plan to drive down the sand spit and have 4x4? If you have a light SUV/Jeep? light truck with oversize tires, then you might get by with 16 psi in your tires on the sand. If you are returning to San Felipe, I don't see any problem with driving the few miles on pavement at that pressure. I'd just air up at the PEMEX in SF. Limit speed to 45 mph. If you bog down in the sand at the higher (16 psi) pressure, then try 12-14 psi. If that doesn't do the job, then there is something wrong, and you should leave. 10 psi is your "insurance" for getting unstuck and getting out of there. I've driven a few miles of pavement on 10-12 psi, 35-40 mph. A wise rule of thumb on the Gulf is, "Always remain above the high tide line." I've extracted so many vehicles in SF area that I never have to buy my own beer!

Quote: Originally posted by Maderita

I have a Viair 400P, portable, 33% duty cycle. Also a Viair 350C Continuous (100%) duty cycle, mounted inside a "fat 50" ammo can for portability. Great units. If you must rely on your compressed air system, it dosen't pay to go cheap. With regard to "Shell Island", I'm assuming that you plan to drive down the sand spit and have 4x4? If you have a light SUV/Jeep? light truck with oversize tires, then you might get by with 16 psi in your tires on the sand. If you are returning to San Felipe, I don't see any problem with driving the few miles on pavement at that pressure. I'd just air up at the PEMEX in SF. Limit speed to 45 mph. If you bog down in the sand at the higher (16 psi) pressure, then try 12-14 psi. If that doesn't do the job, then there is something wrong, and you should leave. 10 psi is your "insurance" for getting unstuck and getting out of there. I've driven a few miles of pavement on 10-12 psi, 35-40 mph. A wise rule of thumb on the Gulf is, "Always remain above the high tide line." I've extracted so many vehicles in SF area that I never have to buy my own beer!

Quote: Originally posted by healthdetective

Another vote for Viair. I use this model. Viair 90P https://www.amazon.com/gp/product/B001MXL71A/ref=oh_aui_deta... Inexpensive but not cheaply made