View Full Version : Sumitomo 2 1/4" calipers on Avanti

07-01-2006, 10:11 PM
Has anyone heard of interference problems mounting these on the original Studebaker caliper "bridge"?

07-01-2006, 10:19 PM
These are the Datsun ones with the larger bleed off holes?? If so,
then they bolt right up - no problems. We put a set on my friends 65
Daytona he had years ago, thats back when you could buy them from a
Datsun dealer for pennies on the dollar compared the the Stude/Jag
ones. Then the Stude/Jag guys found out, then the priced skyrocketed.


07-02-2006, 12:06 AM
The interference issue I'm refering to is where the caliper bridge is "relieved" to insure the passage of the piston as the pad wears down. I realize the pads are "reccomended for replacement" before it reaches that level, but sonmetimes may not get done. Would there be enough clearance for the 1/8th" larger pistom to clear?? I know there are Sumitomo calipers of the 2 1/8 size and they are an identical match to the Stude. I was told the 2 1/4 came from the Toyota Crown of 68 or 69 vintage. "Early" versions had the identical bolt pattern as the Stude, but "later" ones had a larger one that would NOT interchange. (wonder why they changed the mounting???)
Thanks for your input, Tom:)

07-02-2006, 02:05 PM
quote:Originally posted by ROADRACELARK
The interference issue I'm refering to is where the caliper bridge is "relieved" to insure the passage of the piston as the pad wears down.

You got me there Dan .. I have no idea. During my "Studebaker" years,
I didnt have the money to even afford the Datsun pistons, so I was the
guy that had to rebuild my pistons EVERY time I changed the pads!! Now
I am back in the game ... and going new directions.;)


07-02-2006, 08:31 PM
Dan, The Sumitomo calipers are ordinarily sold in pairs, inner and outer halves. The inner half unfortunately has it's inlet and outlet pipe machining designed for use with an internal tube flaring which is not compatible with the Studebaker hydraulic lines. Fortunately the outer half has the bleeder fitting which happens to be the same used by Studebaker. Thus you must purchase 2 outer halves, remove the bleeder fitting from one and install it 180 degrees opposite as an inner half. This will result in a pair of wheel cylinders that will install directly to the Avanti mount and connect with no problem to the existing Stude hydraulic lines. The crossover pipe which carries fluid between the caliper halves will have to be replaced with a Toyota part since the inner half outlet and the outer half inlet internal flair fitting are not compatible with the Studebaker pipe, but this part is inexpensive and should be replaced at the time of any brake overhaul as a safety measure. You need
4 ea. Toyota #47730-30011 Wheel cylinder
1 ea. Toyota #47331-20010 RH hydraulic bridge tube
1 ea. Toyota #47333-20010 LH hydraulic bridge tube
Good luck and lots of money and time in ordering these I did it on my Avanti R2007 about 25 years ago, the parts had to be paid for in advance, no refunds and it took about 3 months to get them. Must have come on a slow boat. The 68 Toyota Crown was the Caprice or Crown-Vic of it's time, they were used as Cop cars and Taxis so I doubt that many are still around.

07-03-2006, 12:33 AM
Thanks for the reply.:) This system I am refering to is already in place on a customers car. The calipers have the inverted flare fitting in all ports...the lines are made up with correct flares and nuts. The bleed screws are a different matter:(. They are currently 10mm with a pointed end...that dosen't work well with the inverted flare!:( No way to stop the leaks with those.. What I need to find are some 10mm bleed screws with the flare on the end and not a point. I've been told there are some foreign cars out there that use them, I just don't know which ones.[?] My main concern was the clearance of the larger 2 1/4 piston going through the caliper bridge. Again, thanks Alan:)

07-03-2006, 04:40 AM
The bleeders on my Avanti have a small steel ball under them, to seal the port. The front cylinders on the car when I bought it were 2 1/8" bore, with "Dunlop License" & "Bendix" cast in. I replaced them with cylinders from SI, (Japenese). Both ports on all cylinders are tapped 3/8" NF. The ports are made to accept a flared tube that is different from the rest of the brake system, (inverted flare?). The bridge pipe has this inverted flare on both ends. The pipe from the inboard cylinder to the hose is inverted flare on one end, and standard on the other. These are stock parts, as far as I know.
Here's one source for bleeders:
http://replacement.car-stuff.com/parts/carstuff/wizard.jsp?year=1963&make=JA&model=XKE--001&category=N&part=Brake%20Bleed%20Screw%20Kit&returnurl=null&dp=false&showdc=true#top .
You can probadly cut the pointed end off the bleeders you have, and use them with a 3/16" ball. See:
http://www.jag-lovers.org/xj-s/book/BleedScrews.html .
As I understand it, the pads "bottom out" in the caliper bridge before the lining is completely worn away. It's a design feature.
Mike M.

07-03-2006, 11:20 AM
That part no. I gave you Toyota (Sumitomo-Dunlop) #47730-30011 includes the bleeder. You might want to check with Dunlop in Coventry, England for the number of the bleeder and where to get them. Could be Moss motors in Goleta, Ca. or Victoria British in the mid-west.

07-03-2006, 11:40 AM
Thanks for the reply. The "original" calipers that were produced by Bendix under licence from Dunlop, did in fact have SAE fittings in them.
I'm not positive, but I think the early Sumitimo 2 1/8" calipers may have been metric. These Sumitimo 2 1/4" are deffinately 10mm metric thread. Because these have the inverted flare "seat" in the caliper, there is no room for the ball AND the bleed screw. The "flat"surface bleed screw pictured in one of the links you supplied, will not seal against the inverted flare either. Again, thanks for your input.:)

07-04-2006, 09:19 AM
I checked the cylinders I had removed from my car. The ports are tapped 3/8" NF; "SAE", not metric. Flares at the cylinders are unusual, (inverted flare?). I corrected my first post.
There should be a "Speed Bleeder" available to fit the 2 1/4" cylinders: http://www.speedbleeder.com/ . There are pictures under "Sizes". "SB10125" has an end that looks like that flare.
Mike M.