I have a 1988 F Super Duty 7.5L/460 v-8 4sp manual transmission I am replacing the Clutch kit.
The Clutch Kit I bought, tells me Ford recommends replacing the slave & Master cylinders and the connecting tubing [braided], when the clutch is replaced, as the New clutch requires more pressure to engage and disengage the clutch plate. This manufacturer recommends this dual cylinder change as well as the tubing, as without it the new clutch may malfunction.
Has anyone encountered the same? Is this dual cylinder change necessary. I intended to replace just the slave cylinder as it is OEM.
I am also experiencing a starting problem. For a while the starter would engage without hesitation with the ignition key and clutch engaged. Then there was a partial connection to the starter from the ignition,i.e. key and clutch pedal down, momentary nothing then a less than complete electrical connection and the starter would engage, and now nothing, when the key is turned and clutch pedal down, Starter will not engage. All indicating lights come ON, nothing else. I have replaced the following over the last 3 months: Starter, solenoid, Igintion key cylinder, ignition module, Distributor cap and wires, distributor Rotor, ignition coil, Clutch interlock switch, both battery cables, thoroughly cleaned the negative ground to frame connection. Thank you for any help. KRis

 

You can try bypassing the interlock switch to see if it's the problem, If it's not the problem them it's probably in the ignition actuator assembly again.

here's a link.
https://www.ford-trucks.com/forums/1...ck-switch.html

 

Mike, thank you for the response. I will give that a try.
7/5 update to Mike1...Tried the Clutch pedal position/interlock switch bypass by jumping the two red/blue trace wires, did not solve the problem. Speciffically the truck still would not start. Went to your 2nd option...ignition actuator switch. I found in replacing the OEM with new, I had not tightened the hold down nuts sufficiently. Also the connecting rod from the key cylinder was stiff in operation. Lastly, the adjustment/placement, I made when installing the replacement Actuator Switch was too far forward for the connection rod. Fixes..adjusted the ignition/actuator switch toward steering wheel, approx 1/4" on the column, tightened the hold down nuts, lubricated the connecting rod at the actuator switch, with these modifications, the truck started. I am still somewhat wary of the fix and will test it out for a few days before figuring it is repaired.
With the actuator issues remedied, the new clutch interlock switch also functioned in a manner I determined to be correct, without the clutch pedal being pushed through the floor board. Thank you for your help. Kris

 

I just fought with this as well (look up my old threads). '87 F250 460 4speed.

Originally I just put a new clutch kit in (upgraded from 11" to 12" clutch). First time pressing on the pedal I blew out the slave cyl. Since this is an external slave it is really easy to just pop off the old one and put on a new one.

My biggest struggle was getting the thing bled! I ended up going through 2 master cyls and 2 slave cyls. Bled inside the vehicle, bench bled by taking the whole thing out, etc. Gave up after trying it for 20 hours or so and took it to a shop, I guess on the trip over there some air must have been knocked loose because as soon as it got there I was able to put it in gear... Go figure.

I'd say try it with the old system, if it breaks then go ahead and replace it. You can have the system off the truck in under 20 minutes as a unit. The headache to bleed it can be huge so I would save it as a last resort.

 

Thank you cx300, I think with your experiences I will heed the FOrd recommendation and replace the two cylinders and line to meet the upgrade. I may still have the bled issues but maybe not replacement of the cylinders more than once. Again I greatly appreciate your assistance. Kris