Stuff that went right --

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Stuff that went right --

Postby jethro » Fri Feb 15, 2019 9:49 pm

This is a mixed topic report-- so Im not sure which subforum it belongs.
I have a 2004 powerstroke 4x4 with a zf-6 trans. The PO yanked the 6.0 and I put in a 12 valve.

I found that with stock wheels/tires (3.73 rear end) that in 6-th I was lacking speed for the freeway.
50 was at an OK RPM but pron not 60. I looked and looked for a gear vendors used for 2 years
but very little available and what was - was trashed. Then one day-out of the blue after having given up-- I checked CL and found one new in the box and the adapter even fit my zf-6. What a find! Took a while to get it all in. Now that I have had a chance to use it a little--- its great.
I only have 1 gear thats duplicated. ( I think 3od and 4) -- but 5-th and 6-th are definitely not
dups. In fact they feel like they are nicely in between. Anyway on the freeway today---- I can go
55-60 at all most like a fast idle with about 5 -6 lbs of boost. Havnt tried stomping on it at that speed yet to see what the boost does. It has the old stock turbo that doesnt come in much intill RPM is about 50% up. So that makes the low end a bit sluggish. The turbo is slobering a little oil and makes a constant stink-- so I may look for an hx-35-- or at least change to a smaller exhaust housing. Had it re-ringed but something messed up I guess. But I just wanted to report how nice the gearvendor unit is.

The other issue was my dragging front brakes. Been through 3 or 4 sets of new brake calipers.
(overhauled units) Taken me a year to go through each part and eliminate it. Buying another caliper wasnt working. (NOW I know why-----) Here is what I discovered. All of the brake
overhaul companies re-use the old phenolic pistons. (except centric) After eliminating every
thing else it came to the pistons. Both fronts were dragging. Pistons were extremely tight in bores. Put 120 lbs of air on them and they would not come out till I wrapped on the housing with a brass mallet. As may dog would say--- "that not right".
So I looked up about pistons---- info on web says the phenolic is hydroscopic--- and they can swell when exposed to water. Also it was said that they may swell after being made if they aernt heat cured exactly correctly. So I ordered a set of new pistons from centric (summit) -- they were about 30$ for 4. After they were put in -they unseated and started moving out at about 20-30 psi. (much better) Today I drove about 35 miles on the expressway and in regular traffic.
at the end of the day the rotors were about 110-115 F. Problem solved. Previously they would be
160F after driving 3 miles.
Another possible problem COULD have been using CRC antirattle goop between the pistons and pads. This stuff could have been acting as a spring and pushing out on the pads even if the pistons were retracting properly. (which I believe they were not)

So- if you but an overhauled caliper - get centric brand. Or order new pistons seperately. all the other ones re-use the old pistons. which appears to be big trouble.

fuel screw!!!!
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Re: Stuff that went right --

Postby 2uphill » Sat Feb 16, 2019 6:43 pm

Interesting bout pistons... I just replaced 2 sets...I’ll pay a little more attention, thks for heads up.
90 d350, SRW, 2wd, 727, stock, except banks i/c, 85K
84 w350 crew cab, I/c 89, s300, 727, 4x4, 130K
90 w350cc, 3.54, getrag, 125K
82 d350 crew cab project
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fuel screw!!!!
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