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What brake system are you running on your TDr?

Home Forums MGTD Kit Cars VW Based Kits What brake system are you running on your TDr?

Viewing 19 posts - 1 through 19 (of 19 total)
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  • #235054
    KentT
    Participant

    @kentt

    What brake system are you running on this much lighter car, that has very little weight in the front — where most braking is normally done?  How satisfied are you with the brakes? Do they seem to “lock up” smoothly and safely with this new weight distribution? 

    Are you considering upgrading them?  To what?

    Discuss!

    Early FF TDr on 69 VW pan
    Slowly coming back from the ashes...

    #259364
    Royal
    Participant

    @royal

    I recently installed aftermarket (SoCal auto) discs up front after a close call that required an emergency stop.  I also installed an upgraded master cylinder.  Installation was very easy.  Braking was markedly improved over standard VW drums.  (I was previously of the opinion that drums were all that was needed.  I was wrong.)  Fronts do seem to lock up first.  I am in process of moving the battery from under the seat to all the way forward which may increase stopping somewhat (and perhaps improve handling by removing weight from the rears and putting it on the front.)  

    #259365
    edward ericson
    Participant

    @edsnova

    all drums. I have a front disk kit to put in this winter with the soob job.

    #259366
    KentT
    Participant

    @kentt

    Roy, there’s two possible easy ways you might change your rear brakes to have them better match the fronts:

    1.  Change the rear drums, cylinders, backing plates and shoes to Type III (Squareback/Fastback) brakes — they’re close to 1/2″ wider shoes, AFAIK
    2.  Change the size of the wheel cylinders on the back to exert more force, by installing front brake cylinders on the rear — I think that’s the way you’d go, and not the reverse — I’d want to confirm first by researching the Kit Car forums on Samba.  But, they will bolt on on either front or rear — they just have different size pistons in the cylinders… (I think the swing-axle/king-pin cars used yet a different size that will bolt in, but I’m not sure.)
    I haven’t gotten that far in my research yet!

    Early FF TDr on 69 VW pan
    Slowly coming back from the ashes...

    #259367
    Royal
    Participant

    @royal

    Kent, I will try to get smart on using my “old” (actually only one year old) front drum cylinders on the back.  

    Thanks, never thought of it.  

    Re using Ty III, I really don’t want to push the wheels out any more, and also I would have to re-drill the new TIII drums for my wire wheel adapters.  Not interested.   Been there, done that.  All done.   

    #259368
    KentT
    Participant

    @kentt

    Doh!  I forgot about your wire wheel mods… scratch easy!  Embarrassed

    I’m still wrapping my head around the whole issue of distance of brake shoe travel versus force applied to the shoe — I just know the wheel cylinders will physically fit on either end of that car… and they’re matched to the braking ability desired on which axle.
    Both these poll questions are inter-related — I fishing for information about what’s being used and what works.  I’ve located a good straight ball-joint beam (with leaves, but no swing arms/spindles/hubs) within driving distance to pick up.  The savings on shipping, combined with the potential of welding in adjusters MIGHT make a disc brake upgrade affordable.
    I’d talked to another guy fairly close about an adjustable beam, but he quoted me $650 ready to install with new balljoints pressed in and my existing drum brake hubs/spindles… 
    I just can’t swallow close to a $1,000 for a new beam with disc brakes, having just incurred the cost of an engine…

    Early FF TDr on 69 VW pan
    Slowly coming back from the ashes...

    #259369
    Royal
    Participant

    @royal

    Don’t understand your brake shoe distance traveled wonderings.  The shoe is going to travel the same distance (assuming they were adjusted the same).  No??

    I think that I remember an adjustable beam for sale at just over $300 at one of the suppliers.  Maybe not.  $650 sounds a bit high.  eh?   
    My disc conversion kit cost right at $200.   Takes about 1 hr to install (not incl bleed time).  Well worth it.  
    #259370
    KentT
    Participant

    @kentt

    Physically yes, but hydraulically no…

    Given the same volume of fluid pumped by the master cylinder, a smaller piston in a wheel cylinder will travel farther (with less force applied to the brake shoe,  requiring greater pedal pressure) than a larger piston ( shorter travel, more force applied, requiring less pedal pressure)…
    That’s what I’m trying to wrap my head around.  I think you want the larger pistons… because the fluid will take the path of least resistance, equalizing pedal pressure between front and rear pistons. But, how much larger may be the $64 question…

    Early FF TDr on 69 VW pan
    Slowly coming back from the ashes...

    #259371
    Royal
    Participant

    @royal

    I hear you Kent, but in the case of brake drums, the distance traveled is restrained/limited by the fact that the shoe comes in contact with the drum.  Therefore, since the shoe is not allowed to travel further, we are only interested with pressure and slave cylinder size.  At the same pressure, the wheel cylinder with the larger piston surface area will exert more force on the shoe (the same pressure or #/sq in but more sq in).  Therefore there will be an increase stopping ability (up to the point of locking up of the rears).  

    I’ll try moving the old front brake cylinders to the rear when the weather changes.  I was unaware that the front cylinders were larger and would fit on the rear.  

    I have to do something if I’m going to beat Ed in this year’s Carlisle Autocross.  Esp now that he is going to be running a Subi.  🙂 
    #259372
    Steve Struchen
    Participant

    @mustang_evets

    What do you do for the speedometer drive when you put front discs on? Is there a provision for retaining the speedometer cable?

    #259373
    Royal
    Participant

    @royal

    Steve, there is no change in the speedo hookup.  Still through the grease cap hole.  

    #259374
    KentT
    Participant

    @kentt

    KentT wrote:
    Dairly close about an adjustable beam, but he quoted me $650 ready to install with new balljoints pressed in and my existing drum brake hubs/spindles… 

    It included the new German/Brazilian ball joints (he insisted on that), labor to disassemble, remove the leaves, press in the ball joints, and reassemble…
    Yes, you can find new beams online for $299 — then add another $100 for shipping, so you’re at $400 before talking parts and labor.
    He builds his own beams from scratch — and they’re much higher quality than the Empi kind of stuff… he ships a lot of them to the  left coast:

    Early FF TDr on 69 VW pan
    Slowly coming back from the ashes...

    #259375
    edward ericson
    Participant

    @edsnova

    Ball joints are like $15 each, pressing them in is a process, say another $20 per… He’ll have an hour or two labor in it. I’d say $650 is not unreasonable.

    Man, it’s expensive.

    until you realize it’s your whole front suspension.

    And you’ll probably never have to think about it again.

    #259376
    Royal
    Participant

    @royal

    I concede!  

    $650 seems in line after I thought about it some more.  
    Are you going to get a narrowed one?

    #259377
    KentT
    Participant

    @kentt

    No, I’m getting a good, straight used stock one.  Then, getting adjusters welded in by my nephew. I’ll transfer everything off my old cut and rotated one myself… 

    That way, I may be able to afford discs for it while it is apart… yet another winter project I hope to get done in my friend’s garage.  But, finishing this engine build is priority #1. 
    Let us know if you try putting front brake cylinders on the rear, and what the results are.  If I put discs on, I have a new set on the front of mine (including shoes, HW, etc.) that have only been bled up and never driven…

    KentT2014-01-15 20:04:33

    Early FF TDr on 69 VW pan
    Slowly coming back from the ashes...

    #259378
    Royal
    Participant

    @royal

    Kent,  

    Carlisle may 16-18.  If you want to get all the credits you deserve.
    #259379
    Hubert Atkinson
    Participant

    @baytowntd

    Question for you guys that installed the disk kits: Did you do a stud conversion, or just used the standard lug bolts?

    #259380
    Royal
    Participant

    @royal

    I did neither.  I bought blank discs and drilled and tapped them to 7/16x24tpi on 4×4.5″ pattern. Installed gr-8 bolts from inside out so they looks like studs.  (This was necessary because I wanted to mount my knock off Triumph wire wheel adapters.)  

    All that being said, why not stick with the standard bolts.  You wouldn’t want studs on the front and bolts on the back.  Would you?  
    #259381
    edward ericson
    Participant

    @edsnova

    I don’t hear a lot of stories about VW lug bolts failing.

Viewing 19 posts - 1 through 19 (of 19 total)
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