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North West Datsun Enthusiasts Forum : Datsun : Trucks
Topic: brakes
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dcboy4031
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Joined: 29 November 2005
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 bullet Topic: brakes
    Posted: 10 May 2007 at 4:16pm

yeah well i have a 75 620 and i cant get any pedal really at all for the brakes. i put in all new rubber lines and bled the piss out of the whole system going in the right order, rear pass, rear driver, front pass, front driver and for some reason i still only have a little pedal at the bottom which means my rear brakes are holding pressure but not my front ones right? i looked all around and cant see any leaks at the master cyl. or the brake pisons is there something im overlooking about the fronts or somwthing? any help is always really appreciated. PS ill have pics of the new core support swap in a couple days

-paul

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motav8td
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Joined: 04 February 2007
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 bullet Posted: 11 May 2007 at 1:30am
When I bought my truck it had the same problem. I found out that it was missing the middle metal plate that connects from the booster to the master cylinder. Once  on it, it worked fine... Hope this helps....
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yello620
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 bullet Posted: 11 May 2007 at 1:36am
Have the brake shoes been adjusted up properly? Adjust all four corners until you cannot turn the drum in either direction. Now go feel your brake pedal. Now readjust the brake shoes until you cant turn them again. Do this a couple of times. With the drums fully adjusted, try bleeding the brakes again. Before driving the truck, make sure to deadjust the brake shoes. I usually deadjust about 6-7 clicks of the adjuster. Also make sure that the adjuster housing slides freely in the backing plate. should slide about a 1/2". You havent adjusted on the parking brake cables have you?
 
Jason
1976 620 L20b 4spd 04 xterra wheels 2056015's lowered 3.5", Front disk brakes.
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dcboy4031
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 bullet Posted: 11 May 2007 at 4:31am
well thanks for all the help but after a lotta hard work it was the master cyl. after doing the adjustment tip and bleeding then until i KNEW there was no air i fugured my problem was in the master so i took it off and replaced it with a newer one from one of my trucks and bam a little bleeding and a lotta brake fluid later i have some brakes thanks a lot for the help though.
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Ol Yeller
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 bullet Posted: 13 May 2007 at 10:24am
Now then your next assignment is to keep up on the adjustment of those brakes...every oil change I ALWAYS do my brakes..3000 miles or less..Pain in the A..? sure, but worth evey minute of your time.....
2nd charter member of the United States Datsun L Motor Cult....In lightweight valve trains we trust..

Ron Kelley & "Ol Yeller" ("73 620...mildly resto'd w/many newer upgrades and 3:70s out back)
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datzenmike
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Joined: 14 April 2006
Location: Canada
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 bullet Posted: 13 May 2007 at 12:21pm
That's right. I had a 521 and every year I would have to remove and
un-seize the adjusters, often breaking one and having to find a replacement for it. I should have adjusted them much more often than I did. Slowly the braking became more uneven and unsafe. I did a lot of off roading and the dirt and water is what did them in.
'78 620 flatbed,'79 dizzy, Bosch 90 amp alt.,p.s.,Z 5 speed, '80 transfer case,toyo 4:10 ft. axle with 4 piston calipers,'85 4x4 wire harness and dash,2oo sx elect. windows, 12.50x33 tires on 82 frame
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