95 F-250 apprx 208k miles

[erichstory]

Greetings...This is my first diesel, mine's equipped w/ an automatic tranny, read somewhere not to run around town w/ the OD engaged, rather to turn it off unless running on the highway...what do you guys think? Also, unless I pump considerable pressure into the brakes before shifting into reverse, I get a "clunk" when tranny engages into R... have been told by two mechanic shops that the "softness" of the pedal is a normal and a function of the rear ABS...had a leak in RF caliper, replaced that, replaced master cylinder, brakes have been flushed/bled three times in recent weeks, brakes feel ok, not soft under load...any feedback on that one? thanx in advance

 

[82fordtruck]

The clunk could be a bad leaf spring on the rear axle. I would just drive it unless it's hunting for gears (shifting a lot back and forth).

Are you saying yourbrakes are fine? I'm not sure I understand the question.

 

[JLDickmon]

no, the brake pedal should be fairly firm.. does it have drum rear brakes? If so, they could need adjusting..
worn center support bearings can make them clunk, as can worn, broken or weak engine and transmission mounts.. better crawl under there with a prybar and start lifting on stuff..

oh, and check and make sure the yoke on the rear diff holds the rear U-joint securely

 

[erichstory]

thanks for replies

Sounds like the clunk's in the rear brakes...any feedback on the "turn the OD off when driving around town" (below 40 mph?) advice I was given?...thanks

 

[trackspeeder]

In stop and go traffic turn the OD off.

 

[82fordtruck]

no, the brake pedal should be fairly firm.. does it have drum rear brakes? If so, they could need adjusting..
worn center support bearings can make them clunk, as can worn, broken or weak engine and transmission mounts.. better crawl under there with a prybar and start lifting on stuff..

oh, and check and make sure the yoke on the rear diff holds the rear U-joint securely

He said it's not soft under a load - I wonder what that means? I read that as they work fine, and he might be talking about the pedal creep you get without a zero loss booster.

 

[82fordtruck]

Sounds like the clunk's in the rear brakes...any feedback on the "turn the OD off when driving around town" (below 40 mph?) advice I was given?...thanks

You were given three or four different places to look - only one was the brakes. Again, the only reason to lock out overdrive is to prevent excessive shifting. Stop and go traffic would be one place that a lot of shifting might happen, or towing in the mountians where it downshifts every hill and you are on the brakes every downhill.

 

[erichstory]

thanks for replies

the brakes are fine, the softness I was feeling seems to be very normal. thanks for the feedback on OD

 

[JLDickmon]

the brakes are fine, the softness I was feeling seems to be very normal. thanks for the feedback on OD

what were they, just out of adjustment?
even with the vacuum pump & booster, the pedal should be high-n-tight.
both RABS and RWAL systems worked identical, the only difference is one was built by Kelsey-Hayes, the other by Bendix..
two solenoids, when a rear wheel lockup is sensed, the first thing it does is block additional pressure from getting to the rear wheels..
if lockup is still sensed, the second solenoid begins to dump fluid pressure..
this can make the pedal feel wierd under operation,
but during normal braking, it should feel like a normal brake pedal.

 

[82fordtruck]

what were they, just out of adjustment?
even with the vacuum pump & booster, the pedal should be high-n-tight.
both RABS and RWAL systems worked identical, the only difference is one was built by Kelsey-Hayes, the other by Bendix..
two solenoids, when a rear wheel lockup is sensed, the first thing it does is block additional pressure from getting to the rear wheels..
if lockup is still sensed, the second solenoid begins to dump fluid pressure..
this can make the pedal feel wierd under operation,
but during normal braking, it should feel like a normal brake pedal.

If you sit there with your foot on the brake, you can feel it leak down. This is normal, unless you have installed a zero loss booster on it. I think thi is what he is talking about. I never notice it unless I just repaired brake problems and am paying attention.

http://www.thedieselstop.com/forums/1270606-post4.html

 

[erichstory]

I brake function seems normal after all, the clunk was the rear brakes out of adjustment, fine now thanks for all the feedback

 

[h2odrx]

I brake function seems normal after all, the clunk was the rear brakes out of adjustment, fine now thanks for all the feedback

Clunkey brakes?

 

[waynebo]

Adjust brakes by finding a big parking lot or a stretch of road where you can see way behind you..now back up and hit the brakes,keep doing this until you have a good pedal,,wayne

 

[erichstory]

I don't know if it's in the brakes or not (I will try waynebo's suggestion)...but once again here's what's going on: when I shift the automatic tranny lever into reverse sometimes the tranny? sort of "clunks" into gear, other times it shifts just fine, nice and smooth (to be clear I am talking about the actual physical part of shifting the truck into gear not the actual tranny shifts, which are fine...I have eliminated everything that a brake inspection could detect, checked and topped off tranny fluid (nice and red and changed 27k ago) any other ideas? thanks guys