More brake woes

[dpuckett]

Coming home today, I went to stop at the end of the balcktop, and the pedal was rock hard. I got home, and looked at a few things under the hood. My first thought was naturally the booster, but I decided to check and see if it was getting any vacuum TO the booster. Took the clamp off, carefully moved my finger to the end of the hose, and eventually put it over the end. No vacuum whatsoever. I thought the pump. But... . Wouldnt i lose my power steering as well? Why no vacuum to the brake booster, but I have my PS? Truck is an early 91 (10/90 build), 5 speed, non intercooled, 259K and some change. I did a search, and didnt come up with much. Vacuum pump is set up different from the intercooled trucks I've had in the past. I'll go out and check the lines and see what kind of shape they are in.

THanks in advance. Gotta run



Daniel

 

[BushWakr - RIP]

The vacuum pump drives the PS pump. You can have vacuum pump go bad on you and still have PS because it's mechanical connection between the two, right were they mate.

The vacuum pump is a tad pricey too... my brother went thru a few of them and the only good thing was that after he paid for the first one, the dealer dropped 7 more in at N/C-Warranty.



Bob.

 

[dpuckett]

Pastor Bob,



Thanks. I ordered a new vacuum pump from O'Reilley's. Kind of on the same level as Checker- not quite as pricey as Napa, but better quality than Auto Zone. Should be here in the AM, $150.



Another question- IS a fading pedal at a light a master cylinder or a RWAL valve? Pedal is kind of low and mushy (when I have vacuum to booster, that is), and you have to keep giving it a little more pedal at a light on a hill. About 5-8 sec, and you have to give it another 1/4" or it will roll. Pumps up and fades right back at the same rate. Fluid got flushed 15K ago (March); wheel cylinders, calipers, pads and shoes all good. Other times it stops ok. Seems a little better if I get on it harder than if I just ease onto it.



Daniel



PS- Pastor Bob- this is unrelated, but what are prerequisites for joining the congregation of Our Blessed Lady of Acceleration Church?

 

[Philip]

IS a fading pedal at a light a master cylinder or a RWAL valve

Most likely the master cylinder.

what are prerequisites for joining the congregation of Our Blessed Lady of Acceleration Church?

Does the term Cha Ching mean anything? If not this should $$$$$. But this makes up for the other item the first time you mash the motor.

 

[jbolt]

Originally posted by dpuckett

Pastor Bob,



PS- Pastor Bob- this is unrelated, but what are prerequisites for joining the congregation of Our Blessed Lady of Acceleration Church?

A heavy right foot- Extra fuel is optional

 

[RamAZ]

Daniel, I just went thru the fading pedal at the stop light stuff. The first thing I would do is bleed the RWAL as the manual says and then the rear brakes. Test drive and try the pedal at the stop lights, if it still fades then I would get another RWAL.



I messed with the fading pedal for 2 months or so and even replaced the booster and got another master cylinder, no luck, Went to NAPA and got a rebuilt one for about 117 or so. Part # is: 570044, there is a 35 core charge. You will have to remove one of the studs on the back of the RWAL to make it fit, at least on my 92 I had to.



The manual says to put the bleed hose in a can partially filled with fluid and then open the bleed screw and bleed. Bleed screw open, pedal pushed down, bleed screw closed and etc.



It takes quit awhile to get all the air out of the RWAL but once its done and bleed the rear and front brakes you will have a good set of brakes.



When I did a complete brake job on the front is when the RWAL started giving me fits. I changed every thing up front, master cylinder, booster, rotors, pads, bearings, seals, studs and hoses, so I was really bummed out when the pedal fading problem started, the end result was the RWAL not the master cylinder or booster. This truck now stops great, even with the cab over camper on it.



Good luck



Jim

 

[dpuckett]

Originally posted by jbolt

A heavy right foot- Extra fuel is optional

Got that already. But it takes nearly a quarter mile to get to the governor (82-83) Where can I get a set of 3. 07s? Also need PODs or some type of custom honed jobs, 3-pc manifold, 4" exhaust... ...



Back on track- I'll let you know how the vacuum pump does tomorrow PM. I'll also look into the RWAL valve. I have it unhooked now for when I need to lock em up NOW. I still cant steer when I hit it that hard, why not have the rears do their share of squalling? Might try hooking it back up.



I bled the RWAL valve, then the rears, then the fronts, as per the instructions posted here. Helped a lot then, but that was 16K miles ago. It was a great improvement then, but it still isnt what the 93 was I had 3 years ago- 3/4" of pedal was locking them up. I'm open to any other ideas. I have enough on the old credit card to get a whole new system, and the MC is original, but if I dont need it.....



Daniel

 

[Philip]

Where can I get a set of 3. 07s?

You have to change out the complete axle assy. The 3:07 rear is a family of its own. The housing is different from a 3:54 and higher gear set. They are hard to find. Dodge has no new housings or complete assy's left in stock. It took six months for me to find a used one. Then I had to do a complete rebuild of the brakes before mounting it.

 

[dpuckett]

UPDATE

Put on new Vacuum pump, no change. Looked into it farther, and took the PS pump assembly off the back of the gear case, and the bearing inside has grenaded, leaving ball bearings all over hte inside of the front cover (I imagine- aint got that far yet). Since the bearing blew up, the plungers for the vacuum pumps arent plunging, and that is why I lost my vacuum. So now what? Does anyone have a PS ass'y for an 89-91? or know where to get one? How hard are they to rebuild? Looks like the only thing holding me back is a lack of a press to remove the gear. Other than that, looks pretty straightforward.



Daniel



Philip- I knew I'd have to change the rear axle hub to hub. Looks like I may have to go with a gear vendor or US Gear OD, if the 3. 07s are that hard to find.

 

[Hutchew]

Hmmmmmmm.........

Originally posted by Philip

You have to change out the complete axle assy. The 3:07 rear is a family of its own. The housing is different from a 3:54 and higher gear set. They are hard to find. Dodge has no new housings or complete assy's left in stock. It took six months for me to find a used one. Then I had to do a complete rebuild of the brakes before mounting it.

This I did not know, I thought it was just a different carrier from 4. 11 down. Learn something new every day, I tell ya... ... ... .



Brannex Truck Salvage in Abq has a wrecked 91-92 CTD Auto (727?) 4x4 Dodge with a Gear vendor unit mated to a NP205, if anybody is interested. Truck has a Banks cooler on it, too.