Cruise Control Quit after Hydroboost Conversion

TrueBurner

Registered User
Joined
Oct 4, 2021
Posts
28
Reaction score
3
Location
California
Have a 1993 F350 7.3idi non turbo.

Swapped out everything new for hydroboost
Master Cylinder
PS Pump
F-53 brake booster
Stainless steal brake lines throughout
Modified location of pedal pin
installed new brake repair kit sw-6350 1l1z-9f924-aa at frame rail (original location unlike some it seems that were attached to master cylinder)
Even went ahead and did a rear disc break conversion while I was at it.

My issue is that besides having a sore big toe because that's all I need to brake now... hahah
My cruise control just simply won't turn on in any fashion.

What I think maybe happened is that I had purchased the different brake pedal switch that was said was needed to make it fit correctly once you adjust location of pedal pin. But at the end of all this I couldn't for some reason get either of them to fit. I ended up putting the original switch back on and making it fit somehow and was just relieved to be done. Didn't think anything of it till I go on a 22 hour trip and CC doesn't work. So I go back and look at the switch and I just think to myself the way I positioned it there's no way it could even function correctly with me tapping the brake pedal to disengage it. lol So with a clear mind I was able to use the new switch and get it in the correct position. But my CC still does not turn on, essentially nothing happens when attempting to use it (no lights on dash or anything).

Is there a way to reset the CC if I fried it somehow by attempting to use it in the wrong position? (don't even know if that's a thing but I don't mind asking dumb questions potentially to learn)

Possibly the repair kit on the rail was defected? (Was new from Motorcraft)

Maybe somehow I loosened a wire on one of the switch connectors?

I just don't know what to troubleshoot or where to start since it's just dead.


Any insight would be greatly appreciated!
 

chillman88

Supporting Member
Supporting Member
Joined
Feb 22, 2017
Posts
6,027
Reaction score
6,155
Location
Central NY
Have you checked visually to see if your brake lights are working properly?
 

Clb

Another old truck
Supporting Member
Joined
Mar 1, 2013
Posts
5,755
Reaction score
2,236
Location
nannyfornia
Tldr
My .02
What changed?
Vaacume leak, blend door work?
 

TrueBurner

Registered User
Joined
Oct 4, 2021
Posts
28
Reaction score
3
Location
California
Replaced everything. Maybe vacuum leak since I just plugged line since it no longer powers vacuum brakes. How would blend door effect cruise control? Had to look up what a blend door even was. The temps and AC work but I have been hearing a random beeping noise when AC is on sporadically. Had no idea what it was, maybe that's the noise?
 

Clb

Another old truck
Supporting Member
Joined
Mar 1, 2013
Posts
5,755
Reaction score
2,236
Location
nannyfornia
Ac and blend door both run off vac.
I was thinking the cruise is also, now I am wondering if I screwed the pooch on this one.
No idea about the beep...
Idi weasels ???
 

Special K

Registered User
Joined
Jul 8, 2022
Posts
24
Reaction score
15
Location
Franklinton, LA
Check above your brake pedal. There is a vacuum switch that could have come unplugged. It runs through the firewall near the brake booster.
 

Ferdy Mint

Full Access Member
Joined
Aug 12, 2021
Posts
125
Reaction score
36
Location
Central Texas
We don't have a 93 here but our older Fords do use vacuum for CC. The CC isn't by wire, it actually pulls the accel linkage, and uses a vacuum diaphragm to generate needed force.

So if you closed off the vacuum before it got to the CC unit, voila there is your problem.
 
Last edited:

Ferdy Mint

Full Access Member
Joined
Aug 12, 2021
Posts
125
Reaction score
36
Location
Central Texas
BTW every PSD we own has needed the hydroboost replaced. Getting spendy these days. Furd product blurb says it's good for only 150k miles "Durability tested to meet 10-year/150,000-mile service life specification"

YMMV as they say
 

Ferdy Mint

Full Access Member
Joined
Aug 12, 2021
Posts
125
Reaction score
36
Location
Central Texas
Another oddity about hydroboosts. One of my sons works FT as a wrench. He's seen Aeronoses come in with stock hydroboost on them. Others have vacuum boost. Go figure. Furd is weird sometimes.
 

TrueBurner

Registered User
Joined
Oct 4, 2021
Posts
28
Reaction score
3
Location
California
Thanks all for your replies! Someone on the forum was extremely helpful by sending me the diagnostic forms. After reading over that I was able to know what I was looking at. I ended up unplugging the connection on the brake pedal in addition to the two under the hood and waiting for a 30 seconds or so then plugging back in. Seemed to reset it and its working great now.

It is a 93 so it is electronic. I believe the first year they switched from vacuum what I looked up.

Thank you all for the input! Much appreciated as always
 

Forum statistics

Threads
91,284
Posts
1,129,800
Members
24,099
Latest member
IDIBronco86

Members online

Top