Hey guys, look forward to some help on this issue.
The truck is a 2007 2500 with the G56 manual and 118k on the clock. Bone stock.
I've been experiencing a clunking/knocking feeling in the brake pedal. It's pretty apparent through the pedal with the clutch depressed coming to a stop on a bumpy road. I can feel it in the wheel but I'm not sure if it's resonating through somewhere else. I've read some threads stating the power steering and braking is interconnected but not sure how that system works. Also there's the common opinion that it's a ball joint since its felt in bumpy roads.
I've thought about getting under and yanking on the steering shaft as well as making sure the brake booster is bolted down securely.
There's a couple threads on adjustable pedals but I'm not sure I have this.
Yep, no vacuum so these trucks use power steering fluid pressure and add on hydraulic hoses and valves to assist with brakes.
IIRC, all Model years 2003-2008, use same hydroboost braking system .
Adjustable pedals, which are electric-mechanical are exposed under dash, look for what should be obvious loose broken parts.
40 lbs required force for activating brakes.
should not need more than that unless there is an issue.
From 04 service manual chapter 5
CLUNK-CHATTER-CLICKING
A clunk-chatter-clicking may be noticed when the
brake pedal is released quickly, after above normal
brake pedal pressure is applied 50-100 lbs
BOOSTER FUNCTION TEST
With the engine off depress the brake pedal several
times to discharge the accumulator. Then depress the
brake pedal using 40 lbs. of force and start the
engine. The brake pedal should fall and then push
back against your foot. This indicates the booster is
operating properly.
ACCUMULATOR LEAKDOWN
(1) Start the engine, apply the brakes and turn the
steering wheel from lock to lock. This will ensure the
accumulator is charged. Turn off the engine and let
the vehicle sit for one hour. After one hour there
should be at least two power assisted brake application
with the engine off. If the system does not retain
a charge the booster must be replaced.
(2) With the engine off depress the brake pedal
several times to discharge the accumulator. Grasp
the accumulator and see if it wobbles or turns. If it
does the accumulator has lost a gas charge and the
booster must be replaced
Thanks - I will do the brake booster and accumulator test but I'm not really having braking issues per say. Just clunking in that connection.
If the power steering pump is failing, what are key symptoms of that? On my other vehicles it starts leaking which is a key indicator. On my dodge, even if the PS pump was going bad I can't figure out how that would cause a clunk.
If hydraboost checks out
Going to have to crawl under truck have some one turn wheel look at track bar bushings ,tie rods pitman arm.
then jack up and check common issues ball joints, shocks, wheel bearings.
From my house looks good.:confused013::confused013:
Is there a link to the manual somewhere? I've found a few expired links on the forum.
Also, what is the procedure for checking hydroboost? I have noticed that my steering is a little stiffer when I get toward full lock, as if the pump isn't working hard enough. Not sure if it's always been this way. I've had the truck for 1800 of my own miles so far.
try searching/contacting member rsauger he has links for FSM
the test I gave you are for hydraboost???
For testing power steering your going to need to have
Power Steering Analyzer Tool kit 6815
Adapter Kit 6893.
FLOW AND PRESSURE TEST
(1) Check the power steering belt to ensure it is in
good condition and adjusted properly.
(2) Connect pressure gauge hose from the Power
Steering Analyzer to adapter 6826.
(3) Connect tube 6825A to Power Steering Analyzer
test valve end.
(4) Disconnect the high pressure hose from the
power steering pump.
(5) Connect the tube 6825A to the pump fitting.
(6) Connect the power steering hose from the
steering gear to the adapter 6826.
(7) Open the test valve completely.
(8) Start engine and let idle long enough to circulate
power steering fluid through flow/pressure test
gauge and to get air out of the fluid. Then shut off
engine.
(9) Check fluid level, add fluid as necessary. Start
engine again and let idle.
(10) Gauge should read below 862 kPa (125 psi), if
above, inspect the hoses for restrictions and repair as
necessary. The initial pressure reading should be in
the range of 345-552 kPa (50-80 psi).
(11) Increase the engine speed to 1500 RPM and
read the flow meter. If the flow rate (GPM) is below
specification, (refer to pump specification chart for
GPM) the pump should be replaced.
CAUTION: The following test procedure involves
testing maximum pump pressure output and flow
control valve operation. Do not leave valve closed
for more than three seconds as the pump could be
damaged.
(12) Close valve fully three times and record highest
pressure indicated each time. All three readings
must be above specifications and within
345 kPa (50 psi) of each other.
² Pressures above specifications but not within
345 kPa (50 psi) of each other, replace pump.
² Pressures within 345 kPa (50 psi) of each other
but below specifications, replace pump.
(13) Open the test valve and turn the steering
wheel to the extreme left and right positions three
times against the stops. Record the highest pressure
reading at each position. Compare readings to the
pump specifications chart. If pressures readings are
not within 50 psi of each other, the gear is leaking
internally and must be replaced. CAUTION: Do not force the pump to operate against
the stops for more than 2 to 3 seconds at a time
because, pump damage will result.
Thanks for all of the information from the manual. Unfortunately I think I could buy a pump and all belts and hoses for the price of the analyzing kit, and have it installed by the time I have it diagnosed!
It's apparent the manual is written for a dealership who has the tools
Yeah, if you don't have right tools or access to them I see $400 or so for OEM parts.
Before I went and spent I'm sure hard earned money , I would first crawling under truck looking for more common clunks/issues in steering that were mentioned.
IMO, would not buy Flung dung Chinese from orielly ,autozone, hepboys , unless you like working on truck a lot!!!!
I'll try the steering shaft grease fix. Don't like the idea of replacing with a plastic zip tie if a metal band was there originally, but they do make stainless ties so I'll see what this gets me. Thanks.
I did the grease on the steering shaft (link from tryNto) about a year or so ago and it fixed my clunk. Pretty quick and easy to do. If I remember correctly I could hit a bump and feel it in the steering wheel and break pedal (foot resting on the pedal but no real pressure.)
I've noticed that my brake pedal has some slop in it as well. I do have adjustable pedals, and before I looked under the dash, my best guess was that there was a bushing on the brake pedal pivot that was worn out. After taking a peek, it appears that the slop has something to do with the adjustable pedal feature. As soon as I move the pedals just a little closer to me, the slop all but disappears. I didn't have time yet to really dig around under there, to see what I would need to replace, (if I even can) to clean up that slop. I'm tall enough, I really do want the pedals at maximum distance away from driver.
Still have not figured this out. From what I can tell I don't have adjustable pedals, and everything seems to be tight. I can now force the pedal to "pop" at a certain point in the stroke. It's kinda concerning me more than annoying me since it is the braking system. I'm close to taking it to the shop to have them diagnose it for the $80 fee, then fix myself as needed based on the severity. From what I can tell it doens't have anything to do with the steering. I climbed under the dash and from what I can see, the slightest movement of the wheel results in an immediate rotation of the shaft. I don't see any slop there.
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