Author Topic: At a loss why my brakes suck  (Read 4198 times)

Offline TonyBolton

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Re: At a loss why my brakes suck
« Reply #15 on: April 23, 2017 - 12:38:18 PM »
Old car show pic I zoomed in on / screenshot...





Offline TonyBolton

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Re: At a loss why my brakes suck
« Reply #16 on: April 23, 2017 - 12:39:15 PM »
Don't be jealous of my heater core bypass hose.  8)  :-*

Offline 1 Wild R/T

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Re: At a loss why my brakes suck
« Reply #17 on: April 23, 2017 - 02:21:57 PM »
Does your booster check valve have an extra nipple? If it does attach a vacuum gauge there & see what you've got....   OE master is 1.125 I'm sure Cass didn't sell you a bigger bore M/C... I think having the vacuum pump in the trunk is marginal & having the reservoir back there is worse.... I've always mounted the reservoir off the diagonal brace under the fender....As far rearward as you can get it to maximize tire clearance...
JS27N0B 70 Challenger R/T Convertible  FJ5 Sublime, Show Poodle w/90,000 miles since resto
WS27L8G 68 Coronet R/T Convertible  PP1 Bright Red, Project
RM21H9E 69 Road Runner Coupe R4 Performance Red, Sold...
5H21C  65 Falcon 2 dr Wagon... Dog Hauler...

Offline TonyBolton

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Re: At a loss why my brakes suck
« Reply #18 on: April 23, 2017 - 03:09:26 PM »
No leaks.....the pump kicks on and off and stays off at its preset range. On at 15 off at 20 I believe

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Offline 1 Wild R/T

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Re: At a loss why my brakes suck
« Reply #19 on: April 23, 2017 - 06:27:03 PM »
No leaks.....the pump kicks on and off and stays off at its preset range. On at 15 off at 20 I believe

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Yeah, at the back of the car, put the gauge on the check valve at the booster..... :2cents:
JS27N0B 70 Challenger R/T Convertible  FJ5 Sublime, Show Poodle w/90,000 miles since resto
WS27L8G 68 Coronet R/T Convertible  PP1 Bright Red, Project
RM21H9E 69 Road Runner Coupe R4 Performance Red, Sold...
5H21C  65 Falcon 2 dr Wagon... Dog Hauler...

Offline TonyBolton

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Re: At a loss why my brakes suck
« Reply #20 on: April 23, 2017 - 06:28:04 PM »
If it was leaking at the booster.....wouldnt it show at the back as well?

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Offline 1 Wild R/T

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Re: At a loss why my brakes suck
« Reply #21 on: April 23, 2017 - 06:36:55 PM »
Put a gauge ion it.... :2cents:
JS27N0B 70 Challenger R/T Convertible  FJ5 Sublime, Show Poodle w/90,000 miles since resto
WS27L8G 68 Coronet R/T Convertible  PP1 Bright Red, Project
RM21H9E 69 Road Runner Coupe R4 Performance Red, Sold...
5H21C  65 Falcon 2 dr Wagon... Dog Hauler...

Offline Beekeeper

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Re: At a loss why my brakes suck
« Reply #22 on: April 23, 2017 - 08:13:24 PM »
Put a gauge ion it.... :2cents:

I'm curious as well to see what the vacuum is at the booster.


Offline xtopfuel

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Re: At a loss why my brakes suck
« Reply #23 on: April 23, 2017 - 09:13:05 PM »
I agree I don't think you have enough vacuum at booster

Offline Beekeeper

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Re: At a loss why my brakes suck
« Reply #24 on: April 23, 2017 - 09:43:11 PM »
I agree I don't think you have enough vacuum at booster

Is vacuum signal something that lessens over long runs? We see drops in voltage when we have long wiring runs with wire that's too skinny. I've never run a long vacuum line but I'm just curious if you can have a similar drop in signal strength over an unusually long run.

Offline 73440

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« Last Edit: April 23, 2017 - 10:01:04 PM by 73440 »
67 440
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73 Barracuda w/ 68 440
65 Plymouth Fury III , I sold ,was my Nana's car till 92 yo.
51 Ford F1 239 Flathead, flipped , new cab , stolen
59 BelAir 283 4 door original patina
01 Chevy van 420, 520 miles
06 Crown Vic Police Interceptor
75 HD Ironhead converted to RH shift
73 HD Ironhead
82 HD Ironhead
74 Norton 850
80 HD Shovelhead
80 Husqvarna WR 390

Offline 1 Wild R/T

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Re: At a loss why my brakes suck
« Reply #26 on: April 23, 2017 - 10:08:14 PM »
http://www.mbmbrakeboosters.com/index.php?option=com_content&view=article&id=12:what-to-do-if-you-suspect-your-brake-booster-is-not-working&catid=7:diagnosing-brake-system-problems&Itemid=15


http://www.engineeringtoolbox.com/vacuum-pipe-line-pressure-drop-d_1197.html


Thank You....  Now if they would just show smaller line sizes....


"Is vacuum signal something that lessens over long runs? We see drops in voltage when we have long wiring runs with wire that's too skinny. I've never run a long vacuum line but I'm just curious if you can have a similar drop in signal strength over an unusually long run."

Yes.... Reason why I asked early on about hose size.... To move the vacuum pump and reservoir 15 feet from the booster he needs at least 1/2" ID hose & 5/8" would be better....  Moving the reservoir closer and leaving the pump in the trunk will help but still isn't ideal..... 
JS27N0B 70 Challenger R/T Convertible  FJ5 Sublime, Show Poodle w/90,000 miles since resto
WS27L8G 68 Coronet R/T Convertible  PP1 Bright Red, Project
RM21H9E 69 Road Runner Coupe R4 Performance Red, Sold...
5H21C  65 Falcon 2 dr Wagon... Dog Hauler...

Offline Beekeeper

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Re: At a loss why my brakes suck
« Reply #27 on: April 23, 2017 - 10:50:27 PM »
Thanks for answering my question. Good to know for future projects.

Offline 1 Wild R/T

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Re: At a loss why my brakes suck
« Reply #28 on: April 30, 2017 - 12:15:41 AM »
Well? Did you put a gauge on it yet?
JS27N0B 70 Challenger R/T Convertible  FJ5 Sublime, Show Poodle w/90,000 miles since resto
WS27L8G 68 Coronet R/T Convertible  PP1 Bright Red, Project
RM21H9E 69 Road Runner Coupe R4 Performance Red, Sold...
5H21C  65 Falcon 2 dr Wagon... Dog Hauler...

Offline xtopfuel

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Re: At a loss why my brakes suck
« Reply #29 on: April 30, 2017 - 06:37:22 AM »
good question, status?