Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
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WORKBENCH ." TRAN S-CA L NATIONALS" By Nate Ra u ba YO U CAN ONLY RA CE ONE . . . NO RTH OR SOUTH, WHICH EVE R SER IES YO U ,S TA R T YO U M UST FINISH. Fluidless brake bleeding hen most peopl e think about bleeding air' from a hydraulic brak e system, they a lmost immediately get a half-filled jar of brake fluid and a short length of rubber hos e from the shelf and a small wrench from the tool box . Then they (or a friend ) pump up the brake lever/ pedal, hold it, and loosen the bleed valve to allow brake fluid to escape, hopefull y a long with an y air bubb les th at may be present in the system. Altho ugh this meth od may work in most cases. Paul T hede of Race Tech came up with a much more efficient way to bleed brakes. T hede 's method removes th e air bubbles. yet pre vents more air from entering the system, and it can be don e with the system comp letely sealed. According to Thede. when the timehonored pump-the-peda l-and-cra ckthe-bleed valve method is used. ther e is the po tent ial for air to enter the system through the bleed val ve threads or through th e bleeder hose apparatus. T here is also the potential for air to be pumped directly into the line if the reservoir drains to the poi nt tha t it's emp ty as th e flu id is p umped out the bottom . T h ere are a lso speci a l va cuum devices which suck bubble-laden flu id do wn. but according to Thede there's not eno ugh fluid flow to be effective. You can also use a squeeze bubble to pump brake flu id into the system from the bleed val ve, bu t you still have a loose valve with the potential for air to en ter the lin e. T hede's meth od is based on the fact tha t air rises in liqui d. T he common met hod attempts to remove air by forcing it do wn the lin e. and since th ere is very littl e fluid flow wi th in' the brake system any tr apped air bubbles move down very slowly. Using T hede's method. the brak e ca liper must be removed fro m it s mount and th e brak e line in as straigh t a line as po ssible. It's also a good idea to be sure there is adequate flu id in the reservoir, as some p u mp ing is required. In sert a screwdriver or other flat . narrow object between th e brake ·pads. leavin g ample room for th em to compress on the object. Pu mp the brake a few times so the pa ds are tig ht . then carefu lly twis t the object to pry the pads apart. wa tchi ng for air bubbles in th e reservoir . Do th is several times and tap the brake line between each repeti tion . As the pis ton is forced back in to the caliper. fluid is forced back up into the reservoir at the top at a mu ch grea ter ra te, carry ing any ai r bubbles to the surf ace. When you 're satisfied that all the air is removed. be sure that the reservoir is fu ll and rep lace the cap. T he ru bber bladder on the top of most reservo ir caps sho uld just touch the fluid . As the pads wear and more fluid is needed in the caliper. the fluid level in the reservoir will drop. T he bladder fills wi th air an d remains on top of the fluid I so tha t no air poc kets can form . Thede recom mends usin g a sq ueeze bulb to fill the line when a new brak e system is insta lled. Once the system is full . then use his method to bleed an y air that remains. GATES OPEN: SIGN-UP: PRACTICE: 1ST RACE: W Wo rk benc h is a weekl y column dealing with moto rcycl e main tenance, p erforman ce a nd equip men t. Have some thing th a i Wo rkbe nc h can address? Drop a line to Work bench . Cycle News , P.O . Box 498, Lo ng Beach , CA 90801-0498. 6:00A M 6:0 0-8:0 0AM . 7:00- 9:00A M 9:30AM SHARP GAT E F EE S: -$10 .00 ENTRY F EES : NO PRE-E NTRY SPORTSMEN· $25.00 PROS· $35.00 SA NCTI ONED Sunday Sunday Monday Sunday NORTHERN CALIFORNIA Sunday AugustLZth Argyll Park *Saturday August 18th Marysville Sunday August 26th Silverstate *Saturday September 8th Sacto Rcwy Dixon, CA Marysville, CA (NIGHT RACE) Carson City,' NV Sacramento, CA (NIGHT RACE) THE "TRANS-CAL FINALE" - COMBINATION OF BOTH SERIES Saturday September 15th Marysville Full DAY of Racing all Classes Sunday September 16th Marysville Points per MOTa all Classes except • ALL S,"" points COUNT • 125/250/500/ Pro T)(-1E3 BIII06ESTORE /UN§TI\~ ~ SPROCKm OOLO SO:R OES PlIO. ~~ ~ ~ s~o;~ U~A ~ .. ~ AUTO MEISTER RAtE 7Er:H i(lAlllrRA ( PETRO TECH ) TERRY CABLE '~J 2000 DflVfl 5,.....,,::>== ""00·'_' $ SUZUKI SAMMY TANNER ·.~ _ . s ~· ~AKE.- C!!¥® .l~ SUS enSion BRAlE-GUARD ...... s,.'.m '. ~ Bajusl!l'l ~C'C', HONDA ~ 6'.'.*u,~- ..--,e 1tJ " , . , ·r FOR MORE INFORMATION CALL CMC @ 714/261-6116 M-F 8:30-5:30PM. . Now Available Through Cycle News Action Theater SUPERCROSS THRILLS, SPILLS U CHILLS (#10 5) Motorsports fans...Hold onto you r seat I Get ready for Supercross Thr ills ...Spills ... & Chills . This new home' video is packed with t he most outrageous & un believable moments in supercross. It w ill put you smack in th e middle of t he action w it h Jeff Ward, Rick Jo hnson. Damon Bradshaw and other supercross sta rs as t hey battle wheel to w hee l...from start to f in is h. it's t he best of th e best! This video conta ins th e most spectacular spi lls , t he hig hest f lying. hardest dr iving. berm bust ing. handlebar banging action ever on hom e video. A Ma diso n Square Garden Home Video Production in associa tio n w it h Seals Commun ications. fr om MotoVideo. To Order Videos, Use The Vid eo Order Blank Elsewhere In This Issue Of Cycle News