2nd Gen Non-Engine/Transmission Exhaust Brake Questions

[surfbeetle]

I'm posting this here since my truck is a 1995 12 valve but this also relates to the 24 valves also. I would like to get an exhaust brake on my 12 valve and I have been looking at used stuff in the classifieds. I see more exhaust brakes for 24 valves than 12 valves and wanted to know what is the difference? Will a 24 valve exhaust brake physically fit on my stock 12 valve turbo? I have seen where some are vacuum and others are actuated by compressed air, are any just cable actuated? I was thinking a cable on the stick shift would be okay. If I were to buy an exhaust brake for a 24, could it be installed on my truck. I would love to just go out and buy a new (and expensive kit) but funds just won't allow it.



thanks all.

 

[Ram4Sam]

When I got mine way back when, I don't recall there being an issue whether it was going on a 12 or 24 valve. I do remember that you were supposed to change the exhaust valve springs on the 12v to get the best performance, this was not required on the 24v. I went with the BD because it uses the vac pump for operation, the other brands need an add on compressor for power... . (that and Piers had a smokin' deal at the time on the BD) I have never heard of a cable operated brake, just vacuum and air operated. It is probably the best mod I made on my truck, you will love it.



Sam

 

[HBarlow]

I used Jacobs brand exhaust brakes on a 24 valve and on a HPCR engine. I l liked the brand. Jacobs brakes use a vacuum pump.

 

[surfbeetle]

Thank you Harvey and Sam. If I can get one cheap enough that's not specifically for a 12 valve then I may try it. I keep looking and hoping to find one that's not a thousand bucks.

 

[KRStone]

My Pacbrake uses the vacuum pump already on my '96. so, just a solenoid, a switch to activate, a switch behind the gas pedal, and the exhaust brake itself.

IMO a good torque convertor lockup switch REALLY enhances the engine brake experience.

If you don't have a TC lockup switch, and you're driving along with the E. B. switch on, and you release the gas pedal, the TC stays locked up, the EB comes on, and you slow down. Let's say you touch the throttle and then release the throttle. The TC came unlocked and you don't have any EB; as a matter of fact the trans is just freewheeling. The only way to keep using the EB is to depress the throttle far enough, and long enough, for the transmission TC to lock up again. I find that unacceptable on steep downhill grades; depressing the throttle while you're trying to maintain a speed or even slow down just doesn't make sense.

If you DO have a TC lockup switch, and you're driving along with the EB switch on, and you release the gas pedal, the TC stays locked up, the EB comes on, and you slow down. You can touch the throttle and release again; BUT the TC stays locked up. So you're slowing down again with the benefit of the EB.

If you're skilled with the throttle and don't mind having a delayed response (waiting for TC to "relock") then you'll be okay without a lockup switch.
If you want maximum (IMO) convenience and effectiveness, consider a something like the BD TorqLoc (that is what I have). There are better options for the newer transmissions.

In my '96, the EB and TC are unable to slow me down, downshift, and continue slowing me down. With the '96 setup I have, the EB will work in the gear you are in and that's it. With my dad's '06, you can take your foot off the throttle at highway speed with the EB on; it will slow you down through that gear, disconnect the EB, downshift, reengage the EB, and continue slowing you down. To the best of my knowledge, due to the relative lack of computing power in the '96 transmission, ours won't do that.

I just wrote all of this and reread your post; you have a manual trans. Oh well, I'll post anyway because some of what I wrote may be useful.
KRS

 

[HBarlow]

MOPAR4LESS used to be an excellent source for parts at discounted prices. Haven't used them in awhile so don't know if they still are.

 

[CKelley1]

your 12 valve has 35 pound exhaust springs. they need to be changed to 60 lb, that is the difference between the 12 and 24 valve ones. now you can get the 60 lbs back pressure for best braking. do not try to use one built for 60 lb with the 35 lb springs or you will ruin the engine. you will need to use a inline one not a elbow type. for maximum braking power stick with the bd or pac air. you already have vacuum and you may be tempted to use it but this is pp way. the vacuum jake uses a hole in the butterfly to limit the pressure to 60 psi, this only occurs at 3200 rpm at sea level. braking power drops as rpm drops and drops as altitude increases. the bd and pac are radically different in how they achieve the ability to maintain 60 psi at all rpm ranges and altitude but the end result for both is the same.

 

[surfbeetle]

Thank you for the responses. KRS, your post is great, while this truck is a stick, if I get another truck it will be an auto. I was aware of the 60 lbs springs and need to get those installed before I do anything else. My wife wants to take the family on trips further from California then we've gone before and I would like the peace of mind to have the EB. This is all great info.

 

[Midnite]

One other thing about the 24 valve exhaust brakes--they are typically wired into the PCM to activate when you pull your foot off the go pedal. The 12 valve ones use a switch under the pedal.

On my 24 valve I went with the pedal switch because the PCM circuitry delays brake activation by about two seconds after you lift your foot off the pedal, something which I didn't like.

MIke

 

[Ram4Sam]

When I installed mine, I just wired it direct to the two speed switch mounted on the stick. I didn't want to deal with the delay from the PCM or with the pedal switch and it's adjustment issues. Having the brake actuate everytime you let off the go pedal wasn't/isn't for me.



Sam

 

[CKelley1]

I did the same as ram4sam

 

[surfbeetle]

I was thinking that I would want it very basic, just on and off on the stick, just like the transbrakes we used to have on the Gillig Transit busses I used to drive. If you wanted the additional braking from the transbrake, you just flipped the switch on, very simple.

 

[Bill Stockard]

I was thinking that I would want it very basic, just on and off on the stick, just like the transbrakes we used to have on the Gillig Transit busses I used to drive. If you wanted the additional braking from the transbrake, you just flipped the switch on, very simple.

If you find a used old style PacBrake that uses the factory engine mounted vacuum pump to activate it from either a 12-valve or a 24-valve, they will interchange. I've done it previously. I had the old style PacBrake on my '97 12 valve and transferred it over to a Y2K 24-valve after I traded trucks. Everything fit and worked great using a 2-speed axle switch on the gear shift lever to activate it. There is a plug in the butterfly that is installed on the PacBrake when it is used with 60 lb. exhaust valve springs. Without the plug, an old style PacBrake can be used on 12-valve engines with the standard 30 lb. springs. I drove my '97 12-valve thousands of miles without the plug before I replaced the valve springs. I called PacBrake at that time and they shipped me the plug at no charge. Actually it is a short Phillips tapered head machine screw with a hex locking nut. The exhaust brake isn't as effective without the 60 lb. springs and the more aggressive braking.



Bill

 

[surfbeetle]

So I looked on ebay and found a BD EXHAUST BRAKE MANUAL SHIFTER PUSH PULL SWITCH and an exhaust brake at this link. Please correct me if I am wrong, is the push pull switch a cable that I could use to actuate the butterfly in the exhaust brake instead of vacuum or air or is this just an electric switch to actuate a solenoid?

 

[Ram4Sam]

That is the same one I got from Piers years ago, it is a elect switch that operates the solenoid valve.



Sam



On edit... . Something looks a bit hokey with that ad. That brake looks like an in line valve, not a turbo mount, and two hundred bucks??? Way too cheap.....

 

[Bill Stockard]

So I looked on ebay and found a BD EXHAUST BRAKE MANUAL SHIFTER PUSH PULL SWITCH and an exhaust brake at this link. Please correct me if I am wrong, is the push pull switch a cable that I could use to actuate the butterfly in the exhaust brake instead of vacuum or air or is this just an electric switch to actuate a solenoid?

The exhaust brake shown in the link is NOT the exhaust brake I referred to in my post. It is not a turbo mount designed for 12/24-valve engines in Dodge pickups. It will require an air compressor to activate it. The BD switch will work switching the exhaust brake on and off. Be sure the mounting clamp will fit your gear shift lever. IIRC, there are two different sizes available.

Bill

 

[mfurrh55]

So I looked on ebay and found a BD EXHAUST BRAKE MANUAL SHIFTER PUSH PULL SWITCH and an exhaust brake at this link. Please correct me if I am wrong, is the push pull switch a cable that I could use to actuate the butterfly in the exhaust brake instead of vacuum or air or is this just an electric switch to actuate a solenoid?

You better check your exhaust size too if you go with this setup, Also that switch seems way too pricey, I would check around some more, you can find used jakes that fit the turbo for a good price, also on the back of your turbo , if you don't have the flange that bolts directly to the brake, i have one that will bolt up, some 24 valve engines came with and without the flange, Good luck ,Monte

 

[Joseph Donnelly]

You can use an exhaust brake on a 12 valve with the standard 35 psi exhaust valve springs. Use one that has a setting (sometimes a plug that you remove from the butterfly) for the 35 psi springs.

 

[Ram4Sam]

You better check your exhaust size too if you go with this setup, Also that switch seems way too pricey, I would check around some more, you can find used jakes that fit the turbo for a good price, also on the back of your turbo , if you don't have the flange that bolts directly to the brake, i have one that will bolt up, some 24 valve engines came with and without the flange, Good luck ,Monte

That price on a off the shelf two speed switch is a bit high but the mount bracket you get is much nicer than the wimpy little bracket that comes with a two speed switch off the shelf.

Sam