We had to use our 10HP QR-25 Quincy compressor a lot today and it is
95 degrees or so. When it gets hot, for some reason it unloads and
runs, but does not pump air. After it cools down, it starts and seems
to pump just fine. Then after a while it unloads and no longer runs.

The only things that I could suspect would be rubber membranes that
push on the unloaders, any other idea?

thanks

On 2013-09-10, BQ340 wrote:
On 9/10/2013 4:57 PM, Ignoramus29430 wrote:
We had to use our 10HP QR-25 Quincy compressor a lot today and it is
95 degrees or so. When it gets hot, for some reason it unloads and
runs, but does not pump air. After it cools down, it starts and seems
to pump just fine. Then after a while it unloads and no longer runs.

The only things that I could suspect would be rubber membranes that
push on the unloaders, any other idea?

thanks


Maybe the hydraulic unloader control on the side of the block? The
membranes usually fail by tearing & you would hear an air leak.

I am thinking, perhaps the lubricating oil becomes very hot, less
viscous, and oil pressure drops, and the hydraulic oil pressure
"safety circuit" causes unloading?

i

On Tue, 10 Sep 2013 15:57:22 -0500, Ignoramus29430
wrote:

We had to use our 10HP QR-25 Quincy compressor a lot today and it is
95 degrees or so. When it gets hot, for some reason it unloads and
runs, but does not pump air. After it cools down, it starts and seems
to pump just fine. Then after a while it unloads and no longer runs.

The only things that I could suspect would be rubber membranes that
push on the unloaders, any other idea?

Newp. Perhaps find a way to run cooler air over the fins via a mister
or water-cooled heads. Just machine some up, Ig. Piece of cake.

--
[Television is] the triumph of machine over people.
-- Fred Allen

On Tue, 10 Sep 2013 22:40:11 -0500, Ignoramus29430
wrote:

On 2013-09-10, BQ340 wrote:
On 9/10/2013 4:57 PM, Ignoramus29430 wrote:
We had to use our 10HP QR-25 Quincy compressor a lot today and it is
95 degrees or so. When it gets hot, for some reason it unloads and
runs, but does not pump air. After it cools down, it starts and seems
to pump just fine. Then after a while it unloads and no longer runs.

The only things that I could suspect would be rubber membranes that
push on the unloaders, any other idea?

thanks


Maybe the hydraulic unloader control on the side of the block? The
membranes usually fail by tearing & you would hear an air leak.

I am thinking, perhaps the lubricating oil becomes very hot, less
viscous, and oil pressure drops, and the hydraulic oil pressure
"safety circuit" causes unloading?

It wouldn't cost much to try a load of better oil, eh?

--
[Television is] the triumph of machine over people.
-- Fred Allen

On 9/10/2013 4:57 PM, Ignoramus29430 wrote:
We had to use our 10HP QR-25 Quincy compressor a lot today and it is
95 degrees or so. When it gets hot, for some reason it unloads and
runs, but does not pump air. After it cools down, it starts and seems
to pump just fine. Then after a while it unloads and no longer runs.

The only things that I could suspect would be rubber membranes that
push on the unloaders, any other idea?

thanks



We have a big pedestal fan to help cool and use synthetic compressor
oil. Do check the unloader membrane and hydraulic air valve.

On 2013-09-12, Tom Gardner Mars@Tacks wrote:
On 9/10/2013 4:57 PM, Ignoramus29430 wrote:
We had to use our 10HP QR-25 Quincy compressor a lot today and it is
95 degrees or so. When it gets hot, for some reason it unloads and
runs, but does not pump air. After it cools down, it starts and seems
to pump just fine. Then after a while it unloads and no longer runs.

The only things that I could suspect would be rubber membranes that
push on the unloaders, any other idea?

thanks



We have a big pedestal fan to help cool and use synthetic compressor
oil. Do check the unloader membrane and hydraulic air valve.

Great minds think alike, we did the same thing.

i

On Thu, 12 Sep 2013 12:53:01 -0500, Ignoramus15426
wrote:

On 2013-09-12, Tom Gardner Mars@Tacks wrote:
On 9/10/2013 4:57 PM, Ignoramus29430 wrote:
We had to use our 10HP QR-25 Quincy compressor a lot today and it is
95 degrees or so. When it gets hot, for some reason it unloads and
runs, but does not pump air. After it cools down, it starts and seems
to pump just fine. Then after a while it unloads and no longer runs.

The only things that I could suspect would be rubber membranes that
push on the unloaders, any other idea?

We have a big pedestal fan to help cool and use synthetic compressor
oil. Do check the unloader membrane and hydraulic air valve.

Great minds think alike, we did the same thing.

If this compressor head has an oil pressure system, adding an oil
cooler is a trivial thing - They make little cooler cores for power
steering on cars and light trucks, or get the smallest automatic
transmission size. A few rubber mounts to attach it to the belt cage,
attach in line.

Then get the soundproofed closet you have the compressor in some
outside air ventilation. Might have to mount a roof jack and a power
vent, and then cut a few intakes in the wall behind it.

-- Bruce --