Changing Brake Chamber Size

[4ways]

The LT625 I’m driving has the 18/24D (Disk) standard stroke brake chambers on the drive axles. The mechanic says I have air back feeding through the rear quick release valve when I’m pressing the foot brake. I have disassembled the QRV and didn’t see anything wrong with it. I’m replacing the QRV with new but thinking a brake chamber might be back feeding so I will be carrying a spare until it does it again (It stopped back feeding before he could show me but he is a trusted mechanic).

So these brake chambers (18/24D) are hard to find and I’ve had problems before when they were hard to find while I was OTR and broke down with shops saying they might not be able to find one locally.

I’d gladly replace 2 or all 4 at the same time to a more common 30/30 size but I don’t know if I can do that. I know I can’t mix and match on the same axle but not sure if I’d have to replace only 2 at a time or all drive cans (4) or possibly the steers as well.

Thanks in advance

[marek4792]

If it's similar to how drum brakes work, one axle can have short stroke and others can have long stroke from factory. My truck, my steer axle and rear drive which both are pancake chambers, and my front drive spring brake chambers are long stroke. In your case though better to replace all including calipers or none to avoid any adverse braking performance..

[Yauchout]

(11-04-2025 )4ways Wrote:  The LT625 I’m driving has the 18/24D (Disk) standard stroke brake chambers on the drive axles. The mechanic says I have air back feeding through the rear quick release valve when I’m pressing the foot brake. I have disassembled the QRV and didn’t see anything wrong with it. I’m replacing the QRV with new but thinking a brake chamber might be back feeding so I will be carrying a spare until it does it again (It stopped back feeding before he could show me but he is a trusted mechanic).

So these brake chambers (18/24D) are hard to find and I’ve had problems before when they were hard to find while I was OTR and broke down with shops saying they might not be able to find one locally.

I’d gladly replace 2 or all 4 at the same time to a more common 30/30 size but I don’t know if I can do that. I know I can’t mix and match on the same axle but not sure if I’d have to replace only 2 at a time or all drive cans (4) or possibly the steers as well.

Thanks in advance

a 30/30 is a drum brake chamber and will not work with disks, your options are a 18/24 or a 20/24 (20/24 being the long stroke option) for disk... the complete axle must match so if you go to a 20/24 on the left front drive the right front drive must be replaced with a matching stroke at the same time...

[4ways]

(11-05-2025 )Yauchout Wrote:  

(11-04-2025 )4ways Wrote:  The LT625 I’m driving has the 18/24D (Disk) standard stroke brake chambers on the drive axles. The mechanic says I have air back feeding through the rear quick release valve when I’m pressing the foot brake. I have disassembled the QRV and didn’t see anything wrong with it. I’m replacing the QRV with new but thinking a brake chamber might be back feeding so I will be carrying a spare until it does it again (It stopped back feeding before he could show me but he is a trusted mechanic).

So these brake chambers (18/24D) are hard to find and I’ve had problems before when they were hard to find while I was OTR and broke down with shops saying they might not be able to find one locally.

I’d gladly replace 2 or all 4 at the same time to a more common 30/30 size but I don’t know if I can do that. I know I can’t mix and match on the same axle but not sure if I’d have to replace only 2 at a time or all drive cans (4) or possibly the steers as well.

Thanks in advance

a 30/30 is a drum brake chamber and will not work with disks, your options are a 18/24 or a 20/24 (20/24 being the long stroke option) for disk... the complete axle must match so if you go to a 20/24 on the left front drive the right front drive must be replaced with a matching stroke at the same time...

Thanks. If them my only 2 options I will stick with the 18/24 and probably pick up a spare to keep as a spare.

I appreciate it.

[Yauchout]

(11-05-2025 )4ways Wrote:  

(11-05-2025 )Yauchout Wrote:  

(11-04-2025 )4ways Wrote:  The LT625 I’m driving has the 18/24D (Disk) standard stroke brake chambers on the drive axles. The mechanic says I have air back feeding through the rear quick release valve when I’m pressing the foot brake. I have disassembled the QRV and didn’t see anything wrong with it. I’m replacing the QRV with new but thinking a brake chamber might be back feeding so I will be carrying a spare until it does it again (It stopped back feeding before he could show me but he is a trusted mechanic).

So these brake chambers (18/24D) are hard to find and I’ve had problems before when they were hard to find while I was OTR and broke down with shops saying they might not be able to find one locally.

I’d gladly replace 2 or all 4 at the same time to a more common 30/30 size but I don’t know if I can do that. I know I can’t mix and match on the same axle but not sure if I’d have to replace only 2 at a time or all drive cans (4) or possibly the steers as well.

Thanks in advance

a 30/30 is a drum brake chamber and will not work with disks, your options are a 18/24 or a 20/24 (20/24 being the long stroke option) for disk... the complete axle must match so if you go to a 20/24 on the left front drive the right front drive must be replaced with a matching stroke at the same time...

Thanks. If them my only 2 options I will stick with the 18/24 and probably pick up a spare to keep as a spare.

I appreciate it.

Honestly, that's probably your best bet. Fortunately, the disc brake Chambers are quite a bit more compact than a drum brake chamber. At least it won't take up a ton of space