Jake Brake

[puller]

I have aa 2006 Ram 3500 with the Jake Brake. The vacuum pump went out at 78000 miles, replaced by a dealer. The cost was $1300. 00 for the job. I asked for the old pump thinking I could rebuild it and have a spare. My question is what goes bad the diaphragm or the pump it self, also how do you get it apart to repair the parts that are bad?



The truck now has 115000 mile on the clock and I really don't want to buy another pump if I don;t have to. Can anyone shed some light on this?



puller

 

[ScottLewis]

Either could go bad but usually it's the diaphram which isn't repairable but can be replaced fairly cheaply if you shop around. Replacing that part seems fairly straight forward.

When my vac pump quit, I just replaced the whole unit with a PacBrake. That wasn't quite so cheap. I can rotate the old pump by the pulley and feel it making suction so I'm pretty sure it was the diaphram in my case. I've pondered fixing it to have on hand as a spare but my Pac is air pressure activated so the entire package would have to be swapped back in.

 

[jhenderson]

Genos has both the complete pump or just the diaphragm assembly at a reasonable price. About a grand less than you paid.

 

[jelag]

I used to sell PacBrake and suggest you consider the change but also used to have several Fords with a diaphragm vacuum pump built by Delco... the pumps would last about 50 or 60K miles before they'd fail and we found that if we gave the pump a dose of engine oil once a year... . a couple of tablespoons to lubricate the reed valves and sort of flush it out... we'd almost double the life of the pump. . we'd pull the vac line to the break booster and check the vacuum with a gauge. . than give it the dose of oil putting a rag over the pump discharge... once it quit spitting oil we'd recheck the vacuum and we'd always see a rise in the value and the rag would be dark gray or black from the dirt in the system...

In some cases we'd have to put a diaphragm in the pump but more often it was just full of dirt...

Of course this isn't in any of the service manuals but it sure worked for us and our Fords. . hope it helps...

One last thought, if you get the PacBrake the same air pump can drive air horns, and air bags on the rear...

 

[Blu-meanie]

Check out the rebuilts at NAPA http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=NVP641015_0131271954

 

[puller]

Thanks everyone for the input, right now I think I will stay with the Jake system.



The bearings seems to be OK, no end play and it turns freely.



Another question if you don't mind.



What kind of oil do you use in the pump itself?



Thanks,



Puller

 

[Shadrach]

I've sold many Jake Brakes but chose to buy a Pac for myself because of pump failures and acc options like Jim said. Shad

 

[AMink]

Check out the rebuilts at NAPA http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=NVP641015_0131271954

Is this a direct swap? Is it hard to put the pulley from the old one on the new one? My pump is rattling big time and I'd rather put in a new pump immediately than mess around with putting the old belt on and bypassing the pump then having to put the long belt on again. That belt is a PIA!

 

[jhenderson]

When I buy one locally, I remove the vac can and mount it on my Jake housing. I change the oil(15w40) measure how much comes out and replace that amount. 9 times out of 10 it's the vac unit that goes bad. If it's the drive unit, ( pump is just a 1 lobe camshaft) it doesn't fit. Best bet for a complete pump is Genos.

 

[AMink]

Does the vacuum unit make a knocking sound like bearings getting eaten?

 

[steve819]

I bought my replacement vacuum pump from my local Cummins depot. Cost was $230. My original one went out @ 70k.

 

[CKelley1]

like stated, get your parts from genosgarage.com if you are going to keep the jake. keep a spare stock belt with you, if the pump locks up it burns the serpentine belt into, as long as it does not take out the radiator you can install the stock belt and continue on. the jake is ancient technology and does not have the stopping power of the pac or bd, both hold 60 psi back pressure from 3200 rpm to idle and sea level to 12,000 feet elevation where the jake is near zero at idle or high elevation. as our jakes fail we switch to bd's. I like the bd better than the pac because of where the compressor mounts. if you go with pac you need to mount the compressor somewhere other than the engine to reduce the high failure rate, we moved ours to the frame.

 

[AH64ID]

the jake is ancient technology and does not have the stopping power of the pac or bd, both hold 60 psi back pressure from 3200 rpm to idle and sea level to 12,000 feet elevation where the jake is near zero at idle or high elevation.

That statement clearly lets me know that you do not monitor backpressure and are making claims based on marketing hype, they don't match the Jacobs or mfgr claims.

At 4500 feet the Jake will build 50 psi by 1800 rpms and 60 psi by 2000 rpms, so from 2000-3200 the braking power is the same. According to Pac their brake builds 60 psi at around 1500 rpms, which is well above idle. The BD closes off the exhaust the same, so it's backpressure will be the same. I have never called BD to ask because I don't like the way they regulate pressure.

Anyhow, even at 8500 feet the Jake will produce full backpressure by 2200-2300 rpms which is not near zero, but it does decrease power at 2000 rpms.

The biggest issue I have had with my Jake is that elevation it doesn't always fully engage the brake. It does sometimes, but as elevation increases the change of a partial engagement increases. A simple depression of the clutch and full power is there, its not really noticeable in braking power until above 5000 but I can see it on the gauge. I have a new pump going in to see if that fixes it.

If I were to start over I would go Pac, but at the cost of a replacement pump vs PXRB it's really hard to justify for the little gains at low rpms where the braking power is reduced on any system.

About 8 years ago there was a rash of bad pumps, but you don't read about them much anymore. The one my Dad had installed in 2006 failed this last summer at about 105K miles with a diaphram tear, the bearings were fine. I am still on the one I had installed in 2007 with 83K miles on the pump, it's coming out to see if that fixes my high elevation engagement, but it might not and that means the pump is still working fine and will go in my cross country spares box.

If your going to bash the Jake be sure to use facts about the Jake and the product you are bashing it with.

 

[nunya]

Had pump replaced once under warranty, that diaphragm died, replaced with one from Geno`s. Not a big job, done in less than an hour. Replaced the oil in pump, ran a separate hose from pump to solenoid eliminating the black plastic tubing it did run thru.............works just like new!!

 

[ScottLewis]

I ran the Jake on my '06 until the vac pump quit at about 60K, then replaced it with a PXRB. Both brakes work well but neither produced 60# back pressure below about 1800 RPM. The PXRB does stay engaged at lower speeds, down to about 20 mph, which I like. I seldom turn the brakes off but recently my PXRB stuck on the closed position a couple of times. I found that the solenoid valve had stuck due to some sort of residue in the plunger chamber. I suspect moisture from condensation had gotten inside. Minor air leaks can lead to more air being pumped, thus more moisture. Cleaning and a light lube got it working again fine and I know where to look if it happens again.
FWIW, I had a BD brake on my '98 12V and with 60# intake springs it was working well when I sold the truck at about 105K miles.
No system is totally foolproof. All may malfunction or not perform up to the hype of advertising. Replacing a diaphragm would have been a lot cheaper than a new brake. My only concern with the Jake was that failure of the pump itself MIGHT have lead to a broken belt and radiator damage.