Ford's answers to the NHTSA 6.7 Investigation

NewsW wrote:

NinerBikes wrote:
New observations on Bosch HPFP's made in Slovakia versus Germany. Full of Pictures. Material changes used in manufacturing... time to find out what Bosch is doing for Ford version CP 4.2 pumps, more so, where are the replacements currently being produced? What country?

pump comparison

http://forums.tdiclub.com/showpost.php?p=3799956&postcount=1706

Here are some obvious differences in a Czech Made 2012 Passat Pump VS our "Regular" German 2.0 tdi Pumps:
.
1.) The Cam has a 0.058" (1.5mm) LONGER stroke.

Major design change, lengthening the stroke and altering the cam profile --- that is a change to reduce the bearing pressure.


2.) The Follower no longer has the coating on it and it is ground to a
much better surface finish. (dweisel already identified this, thanks.)

DLC coating issue.

Big --- and looks like we called that one right on from one of the first posts.

Coating we found to be reactive could have been the issue, but retention of DLC coating on one surface and the other metal suggest something else... discuss below.


Not clear in the pic, but am I right that the piston now do not have a DLC coating on the piston?

Any change in the bore?



3.) The Bearing Material is different and appears again, to have a
better surface finish.

Better the surface finish, the lower the friction.


4.) The pump cover plate is slightly different, only to allow easier
casting /machining.


5.) The Main body is also a different material. Looks more like a
hypereutectic cast material . (More silicon than regular cast
aluminum.)

Does that make the body lower friction and also shed less particles / corrode less given it gets water in it?


6.) The FCV is a different part Number.

Translated: "New and Improved".


7.) All surfaces are finished to a better standard.

.
Here are the similarities:
1.) Same design and principal.
2.) Same aluminum Bore and bore diameter.
3.) Same Diamond coated roller shoe and roller diameter.

[COLOR=]That suggest something not right with DLC coating on DLC coating contact but is OK metal on DLC.

But not an assessment of DLC corrosion per se.


4.) Same High pressure Plunger Diameter and Head with Valve.
5.) Same internal COV valve.
.

OK, what is so different?

DLC Coating on DLC Coating contact seem to be the problem here.

Lowering pressure, friction with new cam profile.

May have altered fluid dynamics properties.

Is there a fluid dynamics problem being solved?

Or is there a sacrificial material approach (using metal on one side) to prevent small damage from growing?

Could it be that DLC coating have different fluid dynamic properties and two surfaces that are DLC coated "shed" lubricant (diesel)?

Is it hydraulic shock?

Corrosion?

Cavitation?

Adhesion of diesel fuel / contaminants to DLC?

Electrostatic properties and contaminants?

Lots to think about.


But my immediate thought is a deal is being hatched once this pump is validated in enough customer hands.

Please PM me regarding the last sentence, ie what does this mean to me if I own a Jetta or Golf or Sportswagen TDI? VW quietly goes about replacing the failed units, or is it enough of a safety hazard that a full blown campaign /recall goes into effect to avoid the collateral damage the first 4 years of pumps ending in P/N 155 A create. My 2012 Passat is the newest version with the part number ending in 155 E.

This still means that I am a BETA tester... Thanks, Bosch.

My personal feelings are that every accountant, every Doctor, PHD or Engineer at Bosch that had a hand in this pump pricing, design, material selection, and development should take a long summer vacation in a Ford or a TDI driving from Florida to San Diego and back with their family, babies, and grand parents in the vehcle, so they can experience failure first hand in the summer heat, and worry about their vehicle and the rest of their family, all at the same time. Maybe then, they'll come up with a better idea. Better yet, laps aroudn the old Race Track in Death Valley, CA.