Engine/Transmission (1994 - 1998) Help-----this is scary!!!!

[Dutch & Di]

This has happened twice. Once about 2 years ago and then again yesterday.



The first time we were cruising down the highway hooked up to our 38' 5th wheel minding our own business when the cruise & the air conditioner shut down. I realized we had no vacuum and no brake boost. Since we were hooked up to the 5th wheel, the trailer brakes stopped us. I turned the truck off and checked vacuum lines and all looked good. Restarted engine and viola` everything ok-hmm.



Fast forward 2 years. We pulled into an RV rally hooked up. While waiting in line I turned the truck off. I started the engine, moved up in line then tried to stop. No brakes, uh, oh no vacuum. Got parked, turned off truck, checked all lines again all ok. After setting up our 5th wheel, I got out the vacuum gauge & had good vacuum. The brakes were ok again.



Scary huh!! Help??? Diana

 

[gathomas]

My "97" Dually - brakes are Hydraulic, called Hydro Boost if I recall. is Vacuum required for operation ?? I don't think so, but I could be wrong. Since yours is a "96" it could be different. Someone on this site will know. . be patient Diana

As far as the Vacuum & the A/C and Cruise - check the main Vac line coming off the Vacuum Pump - I had to replace mine years ago. Good luck - Glen

 

[fest3er]

This has happened twice. Once about 2 years ago and then again yesterday.



The first time we were cruising down the highway hooked up to our 38' 5th wheel minding our own business when the cruise & the air conditioner shut down. I realized we had no vacuum and no brake boost. Since we were hooked up to the 5th wheel, the trailer brakes stopped us. I turned the truck off and checked vacuum lines and all looked good. Restarted engine and viola` everything ok-hmm.



Fast forward 2 years. We pulled into an RV rally hooked up. While waiting in line I turned the truck off. I started the engine, moved up in line then tried to stop. No brakes, uh, oh no vacuum. Got parked, turned off truck, checked all lines again all ok. After setting up our 5th wheel, I got out the vacuum gauge & had good vacuum. The brakes were ok again.



Scary huh!! Help??? Diana

It's possible that in checking the various lines, you corrected the problem without knowing it. The easiest place for vascuum to be interrupted is in the joint on the output of the vascuum pump. If the line is pushed too far in, the flow of air can be blocked. I've no clue how this joint can work itself farther together without human assistance.



It could also be any number of other problems.

 

[wcjp]

My "97" Dually - brakes are Hydraulic, called Hydro Boost if I recall. is Vacuum required for operation ?? I don't think so, but I could be wrong. Since yours is a "96" it could be different. Someone on this site will know. . be patient Diana



As far as the Vacuum & the A/C and Cruise - check the main Vac line coming off the Vacuum Pump - I had to replace mine years ago. Good luck - Glen

His 96' brakes are completely different than 97'+. On my 96' I had vacuum leaks at the transfer case. When you get home it might be good preventive maintenance to repair the vacuum pump/power steering with new seals.

 

[Missouri Mule]

94 to 96 2nd gen used vacuum to operate brake booster (97 on up used a hydraulic booster).

Check vacuum check valve at booster also there is supposed to be vacuum check valve near the vacuum pump (There was a recall to put a check valve in the main vacuum line).

 

[surfbeetle]

Replace the vacuum line that goes from the pump up to the brake booster, it can collapse. Also, you need to check your connections on the smaller lines that T off of the vacum lines. Check for the recall on the vacuum pump, some needed to have a check valve installed to keep oil out of the vacuum line. Also, there is a rebuild kit available from FIXINRAMS.COM that fixes the oil leak between the power steering pumps and the vacuum pump. Good luck.

 

[Dieseldemon]

You could change it over to the Hydor Boost System it is a much better system

 

[surfbeetle]

It may be a much better system, but in my opinion, the stock system is fine as long as it is functioning correctly.

 

[Dutch & Di]

Thanks so much for all the replies, input and suggestions. I printed them out for Dutch and he is going to check things out this weekend when we settle into an RV park in Indiana this weekend. Diana

 

[Dieseldemon]

The vacuum sys works fine as long as you don't have to hit the brakes several times in qiuck secession then you run out of vacuum.

 

[jdiller]

How do you change it to Hydro boost? Anybody make a kit?

 

[Forrest Nearing]

very easy, you can get the parts at any parts store...



I would put an exhaust brake on the truck

 

[WOTURBO]

I changed my 95 over to hyd. Boost about a year ago. I got tired of the vaccum booster setup. I liked the feel of the hyd booster when i drove my cousins 97. I went to the wrecking yard and got the master cylinder/hyd booster ***. With the power steering hoses as well. When i first went to do this switch i ordered a h/booster and then found out i need the other parts. I just used the one from the wrecking yard as a core. You will need the metal pipes and spacer block and push rod between the m/c and booster. I'm not sure if you can by them seperate from dodge. I just unbolted the m/c from the v/booster and slide it forward with the brake lines still connected. Removed the v/booster from the truck. Installed the spacer block and push rod and pipes onto the remanh/boost, then slide the m/c back into place and bolted it back together. I ordered new power steering hoses for the 97 truck and a reman power steering pump. I used my old p/s pump as the core. In short i just used parts out of a 97 truck, the set up works out great. And looks stock.

 

[Dieseldemon]

All the parts are available from Dodge as I have bought them and have an extra spacer on hand.

 

[Extreme1]

I bought a complete set up from RedlineAR on eBay (he parts out Cummins powered Dodges), included the booster, master, mounting block, pump and hoses for about $75.