Blue Ox

Thanks again fjh! According to the service manual I have the e7 valve springs had to be replaced with 190 t0 210# valve springs which is what the etech standard springs are in the book. I don't have the long down hill grades like out west so I may not have the same issues. I will try it if it works good if not I try a telma.

I have everything to put the exhaust brake on. I can't find any reason it will cause major issues, like valves hitting pistons. I think I will try it, if I find any issues I will take it off.

Mack had the stealth brake that was both jake and exhaust brake from what info I can find. I know of older macks with exhaust brakes and the guy who drove them said they worked fine.

Thanks for the warning! I found some oil in my air pipe so I am going to swap turbos before it fails maybe get one with the better seals. I can hold it with the jake and keep it at 1800. I really just want some extra, more braking the better.

Thanks for all the help. I can't find a reason not to use the brake. I'm down for mud season so I have time to look around some more before I install it.

Just called pacbrake. They said they don't do anything with macks???? I am thinking the chart I found on they're site isn't much value.

Would there be another reason for them saying 20#?

My son in law works for ny state dot and says they run exhaust brakes on their macks. Going to try to find more info from them

From what I can find they are 1.573. I should have plenty of spring.

the service manual I have says valve springs are 190 to 210#. That is what is confusing. Why would pacbrake say 20#?

Others are 45 to 80#. The pre etech e7 is 45#. I can't figure out why the etech would be so low. I have a jake on the truck and is working as good as expected, just looking to help it.

Pacbrake has a spring on it that controls the back pressure. I just found their application chart that lists the etech being limited to 20#. Don't think that will give much braking .

The telma will add about 700#. The maintenance is not bad, really just the bearings as far as I have found so far. The exhaust brake is simple enough, my concern is the back pressure. I have found one place that says the etech is limited to 25# back pressure. I don't want to have the valves float and hit the piston. I am going to try pacbrake today and see what they say.

Thanks for the reply. I have been studying their site. I really like the idea of the telma, wish I could see one in operation. I am just weighing the cost of each. I think in the end I would be happier with the telma.

I am looking at a frame mounted one. I have a pacbrake off a c9 that is rated at 40# pressure. I found one place that said no more than 25# on an etech so I don't think I will use it.