Danchuk Catalog Classic Industries
American Auto Wire
Classic Performance Products
Hellwig Products IncPerformance Rod & CustomNu-Relics Power Windows




Username Post: Wilwood Master Cylinder Conversion (WHICH Pushrod?)        (Topic#360328)
redlinetoys 
Senior Member
Posts: 1543
redlinetoys
Reg: 04-17-04
03-30-20 03:16 PM - Post#2789827    

Hi guys, Been a long time since I have been on here. Car has been sitting in storage for a few years and am finally getting it back on the road after a LONG slumber.

I have 4 wheel drum brakes with the stock master. I have purchased a Wilwood Master Cylinder which I will use as a manual kit with proportioning valve, etc.

I am aware of what needs to be done with the lines to divide the system properly.

Here is my only question. With this master bolted up to a stock 55 Chevy setup (No power assist), will the existing factory pushrod work? Do I need to purchase something else or custom make something to make this master a true "bolt in"?



Bob
RedlineToys



http://www.youtube.com/watch?v=GslLKzhPth8





 


5Larry7 
"17th Year" Gold Supporting Member
Posts: 2014
5Larry7
Loc: Dallas, TX
Reg: 05-17-04
03-31-20 09:26 AM - Post#2789897    
    In response to redlinetoys

Most manual master cylinders use a "long" push rod, while power master cylinders use a "short" push rod. I would compare the old master cylinder, i.e., the depth of the piston in the cylinder with the depth of the piston in the Wilwood cylinder. If they are the same or nearly so you should be good to go. If not some adjustment will be have to be made. One more point, be sure when it is all installed there is some play or distance between the end of the push rod and the piston in the master cylinder. If there is no play it could result in the brakes not releasing as they should.

'57 210, 327 cid, Holley MPFI, 700R4, A/C & more.
'51 Studebaker Starlite coupe, 350, TH400, GV OD.
'96 Replica of a 1950's Teardrop Trailer.


 
redlinetoys 
Senior Member
Posts: 1543
redlinetoys
Reg: 04-17-04
03-31-20 10:36 AM - Post#2789904    
    In response to 5Larry7

Good info Larry. I appreciate it!

I was hoping to understand the needs better before tearing apart a running/driving car. I realize this is kind of a minor build issue (I built the car from the ground up). Was just hoping to hear from someone else who had installed the same master into a 1955 without power assist.

I bought a complete kit with the bracket and proportioning valve and am anxious to find some time to put it in.

Wilwood Part Number: 261-13626-P

Bob
RedlineToys



http://www.youtube.com/watch?v=GslLKzhPth8





 
acardon 
Ultra Senior Member
Posts: 11389
acardon
Loc: DFW TEXAS
Reg: 03-25-05
03-31-20 02:26 PM - Post#2789920    
    In response to redlinetoys

Looks like it has a pushrod. The clevis may be a different thread but I bet they are the same.
https://encrypted-tbn1.gstatic.com/shopping?q=tbn:...

Don
66 Corvair (driving)
57 2dr HT (driving)
56 2dr HT (waiting to be restored)


 
Rick_L 
Member #409
Posts: 27736
Rick_L
Loc: Katy, Tx, USA
Reg: 07-06-00
03-31-20 04:52 PM - Post#2789931    
    In response to acardon

The master cylinder you're looking at has a 3" long pushrod with a 3/8"-24 thread. That should be in the ball park but might be a little short. Probably doesn't take much to lengthen it or maybe Wilwood has a part that will do that.

The one you're looking at has a 15/16" bore. They do make a 1" bore master cylinder that doesn't have a pushrod that can use the stock pushrod.

I have no idea why they don't offer it in 15/16". Curiously, I didn't see a pushrod version over 15/16" bore either.



 
redlinetoys 
Senior Member
Posts: 1543
redlinetoys
Reg: 04-17-04
04-01-20 11:16 AM - Post#2789994    
    In response to Rick_L

Great info guys. Much appreciated.

It sounds like it will be reasonably simple to fab up the pushrod to attach properly to the stock pedal.

I ordered the 15/16 as a reasonable "in-between" size that would work with my current manual drum brakes, but also would be compatible with future front discs.

Really appreciate the help and will post up how things work once I get there...

Bob
RedlineToys



http://www.youtube.com/watch?v=GslLKzhPth8





 
Rick_L 
Member #409
Posts: 27736
Rick_L
Loc: Katy, Tx, USA
Reg: 07-06-00
04-01-20 05:15 PM - Post#2790030    
    In response to redlinetoys

What are your future disc brakes? If you use GM iron calipers, you would be as well off with a 1" bore.

If you are going to use aftermarket or Corvette calipers, you might need 7/8" anyway.



 
redlinetoys 
Senior Member
Posts: 1543
redlinetoys
Reg: 04-17-04
04-02-20 08:31 AM - Post#2790091    
    In response to Rick_L

Yes, I gave a lot of thought to the optimum master cylinder size.

Ideally, it would have been best to upgrade the master and front brakes at the same time. However, I am not in a position to buy the front brakes I have chosen yet.

Before purchasing the 15/16 master, I contacted Wilwood Tech Support to discuss the situation with them in detail, including which specific Wilwood front discs would eventually be utilized.

There was considerable conversation regarding the choice of a larger or smaller piston size (depending on manual 4 wheel drums vs front discs). In the end, the thought was that the 15/16 master would give a reasonable "in-between" size" that would work fairly well with either setup.

I will use it for now with my drums, and see how it works with discs later. If there is an issue, I will upgrade the master size again (though I am hoping that doesn't happen as I have spent this week grinding away the casting marks and highly polishing the current master! )

Bob
RedlineToys



http://www.youtube.com/watch?v=GslLKzhPth8





 


Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

306 Views
FusionBB
FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.15 seconds.   Total Queries: 15   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 08:55 PM
Top