Engine/Transmission (1994 - 1998) Calling all Ex.-brake users (Pacbrake specifically)

[Got Smoke?]

I've got my PacBrake installed and will finish wiring it tomorrow... ..... but I can't get my 60lbs springs in till next weekend at the earliest.



Just like anybody with a new toy I'd like to use it here and there... . kinda start getting acustomed to it.



Until I can get the 60lbs springs in however what RPM should I stay below while engaging the brake? I WON'T be towing, just driving back and forth to school and work.



Thanks,

 

[Kalaehina]

Mark, did your brake have that "hole" in the flap, I think if it did it's all right to use it with the stock springs. I left the one in my brake open but still put the 60lb springs, something like if you leave it open then it's ok with just stock exhaust springs and/or the heavier duty ones, but if you plug the hole then you have to use the 60lb springs. Not totally sure on this theory but I think that's what it said. As far as RPMs go, the brake won't feel that effective under like 1750, over 2000 it's very noticeable, course I only know how it feels unloaded. Maybe some one else can supplement this info. Hope this helps a little.....

 

[Got Smoke?]

Originally posted by Kalaehina

Mark, did your brake have that "hole" in the flap

Nope bought it off Csevers and his is a 24V. No 2nd hole on 24V brakes

 

[Steve Campbell]

Just a guess based on RPM and spring strength...

keeping the engine below 1900 RPM should not stress the system at all.

 

[TPCDrafting]

If it were me, I'd wait for the springs. But that's just my opinion. There is really no "getting used to it". It's so easy to use, it becomes second nature in about 2 minutes. Floating a valve and causing some real serious damage wouldn't be worth it to me. Keeping it under a low RPM won't help you anyway, you won't feel anything, just the sound it makes. Again, JMO. Once the springs are in, you'll love it!!

 

[willyslover]

Im with TPC on this one ... . not worth tagging a valve, sometimes safe is the better bet

 

[crabman]

H.D. Ex-Springs

I agree with TPS & willyslover not sure about the HD E/S, but why take a chance. Could be big $$$$.

The PacBrake was one of the first aftermarket installations and I consider it one of the best. I hardly ever turn it off and when I do it is like Wholly ***** happened to my brakes.

I think that you will be after the HD E/S installation and start using it. It will slow your truck down tremendously especiaily with a 5 speed. Just play around with it and you will figure out when you can and can not engage it when downshifting for stopping/slowing down.

 

[Got Smoke?]

Thanks for all the replies... ..... swap'n trucks with dad to see about getting my truck into a shop in the next couple of days for the HD Ex. springs.



Got the Pac all hooked up to the vaccum pump tonight... . jumped it from the vaccum switch to the battery just playing to see how if it was working properly all seemed ok!



Can't wait to get my HD springs in!Oo.



One more question..... I've heard in the past that with the brake on EGT's would rise to anywhere between 300-450. Mine never got above 250. What gives?



I double checked and triple checked with Pac before drilling out the hole in the butterfly for my 12V. 31/64's was what I drilled it to. Do you think it will change once my HD springs are in?

 

[SRehberg]

If you call PacBrake, they will tell you that on the earlier 12V engines with the stock springs, if you leave the holes open, you can use the brake all you want without worry. They even comment it is good in the stock configuration up to around 11,000lbs of load. Over that, they recommend the use of 60lb springs in all cases, but as far as valve damage, they say it's o. k. with the holes open. I own a '96 with the stock springs, and it works o. k. for me; one day I'll go for the heavier ones, then I can use the full potential of the brake.

 

[Got Smoke?]

Originally posted by SRehberg

If you call PacBrake, they will tell you that on the earlier 12V engines with the stock springs, if you leave the holes open, you can use the brake all you want without worry. They even comment it is good in the stock configuration up to around 11,000lbs of load. Over that, they recommend the use of 60lb springs in all cases, but as far as valve damage, they say it's o. k. with the holes open. I own a '96 with the stock springs, and it works o. k. for me; one day I'll go for the heavier ones, then I can use the full potential of the brake.

I bought my brake off of a 24V member, the 24V brakes don't have the 2 holes like the intended 12V brakes do.



I already stated this too, but thanks for you response.

 

[TPCDrafting]

I only recently put in guages and noticed this past weekend pulling about 9000# of horse flesh/trailer over a pass that with the brake off, it was cooling to around 300. Once I turned the brake on coming down the hill it took a mile or more when I noticed my pyro read around 600, so I believe your question answers true. Someone with more experience towing with gauges and pac can answer truthfully.

 

[willyslover]

with the holes you might not see the added temps quickly or at all... and it takes a few/couple min. to see the higher temps above 300 or so... BTW if you didn't see anything about warm up's... great tool to use on the winter cold days to warm the motor ... especially in snow areas. .

 

[onestackdram]

Ok well having larger ex. springs is new to me. I have had my brake in about a month and half. and have used it both towing approx. 30k and when completely empty and it seems to be running just fine. And at any RPM I can feel it stopping the truck. I also bought mine off a 24v owner. So mine doesnt have any holes in the butterfly. Now does any of this matter that the brake is a BD brake? I would assume not. but what do I know I never claimed to be smart. I even spoke to BD when I was installing it to double check everything and EX springs never came in to the conv. Someone correct me before I tear something up in the motor.



Thanks

Russell

 

[BWilson]

I would think you could get by for a while without the springs. Just don't tow, and try to keep the rpm's below 2200 or so with the brake on. The spring install really goes pretty easy, or at least, much easier than I expected. Just leave the beers in the fridge until you're done. Those valve keepers are REALLY small!!!



As for the BD brake comparison, the BD uses some internal valving in the cylinder to regulate back pressure. The pacbrake uses one or two holes. One with 60# springs, two without (for 12 valver's). I have 60# springs and one hole open. I have used it for 250 - 300K miles and just love it!!!