Sorry, i guess i cant read. You are correct. 350 does have hydro boost. again my apoligy.

 

Vacuum boost here...no issues, stops on a dime towing or not. I believe all diesel 250's have vacuum and 350's have hydro.

 

The kickback I am talking about is substantial. I have been driving with hydro-boost since 1995 up until purchase of my new truck. It didn't pop up on the 08 until after many miles. I actually did the below steps w/o the filter and it helped; but, you can find posts for the same problem in the 6.4 forums where people ended up with the hydroboost replaced (mine was not). On my 95 GM I did have to have it rebuilt.

Ford must have something above normal too:
TSB 07-11-10 May 23, 2007; supersedes TSB 99-25-8 to update the vehicle model years

Some 1999-2008 F-Super Duty, 2000-2005 Excursion, and 1997-2007 E-Series vehicles equipped with Hyrdo-Boost® brake booster system may exhibit a brake pedal kickback and/or grabbing condition when applying the brakes. This may be caused by contamination within the power steering system.

The proceedure is to temporarily install a filter, turn the steering lock to lock 25 times; pump the brake petal to the floor 25 times; turn steering lock to lock 5 times; remove filter.

"With the engine at idle, gradually apply the brake pedal until fully applied. If the brake pedal kickback persists, replace the Hydro-Boost® brake booster. Refer to WSM, Section 206-07."


Bob

 

Mine new 2012 F-350 SRW has vacuum boost; I walked out in the rain and raised the hood to double check.

This is from an order guide for 2012 last year:

•

—

—

—

• Engine block heater

This file was at one time on profleetsales.com site (Bobby Williams at Sunrise Ford) Now he posts the whole Ford order guide and I can not find anything about hydro or vacuum for super duty.

However, the guide I cut and pasted from is still available in a link in this thread:
2012 Super Duty Order Guide - Diesel Forum - TheDieselStop.com

Of course I had to paste a little more: says Engine block heater standard; mine was an option (or at least the cord was).

So I know the specifications say one thing; but I also know what I got

Bob

 

Whats an easy way to tell by looking under the hood

 

The black hose is the vacuum hose; it angles down to the white check valve on the large round disc like vacuum booster. Note location of master cylinder is just under the brake fluid reservoir.

I also found link to a later and only the 2012 Super Duty order guide; but still no vacuum vs. hydro-boost information.

http://www.profleetsales.com/pdf_fil...Y%20PICKUP.pdf

Picture is from my 2012 F-350.

 

Wow, so I guess another change for the '12's is vacuum on all 250 and SRW 350 with hydro only on DRW vehicles. I wonder why they decided to do that? Seems strange.

 

So I'll ask again like I asked earlier, where do you find this info? The document that I uploaded suggests that the diesel F350s have hydroboost for 2012.

 

Well it would seem the early order guide was in conflict with the specification document. Maybe it is like the finned rear differential covers

The later order guide doesn't touch the subject; but the earlier one called for Hydro-boost only on DRW. The specification document is dated 6/2011 IIRC too; although a copy I have saved had a creation date in September 2011.

http://media.ford.com/images/10031/2...Duty_Specs.pdf
above document calls vacuum for F-250 & F-350 SRW
dated June 2011.

Mine is a 2012 Job 1; and it is a F-350 SRW with vacuum boost.

Few more months we can see what they are publishing for the 2013 models

Maybe the power tailgate lock and a camera looking at the fifth wheel hitch.

Bob

 

Now that's just weird. Looks like they carried over that section of the vehicle specification document from 2011.

So the SRW PSD F350s do have vacuum brakes. Looks like Hdslider and mach are correct! Much like the rear diff cover I don't see the hydroboost vs. vacuum boost brake thing as a meaningful change. Either one should be capable of locking all four tires at max GVWR, and anything beyond that is just pointless IMHO.

 

Well someone said there is no logic to getting the finned vs. stamped steel differential cover; maybe it is a supply and demand thing since the later order guides seem to not mention it. I didn't look under the hood at the other F-350's so I don't know what they had.

I have a stamped steel rear differential cover; and a steel engine oil pan. I have the same drivers floor as the 2011 models.

So far my new truck is <S>meeting</S> exceeding all my expectations.

Bob

 

They just feel different. I shot videos of my foot stepping on the pedal of my 6.2L rental and my 6.7L truck but without some measurements I felt that it didn't really show much.

That's right, the vacuum boost system doesn't have any issue stopping the vehicle... in fact I wasn't used to how little force was required to apply the brakes that I accidentally tested the ABS on the rental truck the first time I stepped on it, expecting to have to apply the "usual" amount of force to do the job but turned out to require significantly less. I never got used to it over the week I drove the gas truck - it has a 'hard knee' (if you graphed it) where the first few mm of pedal travel doesn't do anything and then suddenly it grabs. There is basically no resistance to your pedal stomping and vehicle braking force is really how far you push the pedal. On the other foot, with the hydroboost system, there is resistance to your pedal application - the harder you apply the brakes, the more it fights back at you. It's like working against hydraulic pressure resistance versus a return spring in the master cylinder or vacuum booster. I'm sure that if you drove only one vehicle all the time it wouldn't actually be a problem.

Let me recycle this image that I posted in another thread with the same topic:

 

Hi bob,
What's the build date on yours? Mines a 12 with the plastic oil pan.

Thanks
Bob

 

My build date is 12/09/2011

Bob