Home » Public Forums » GMCnet » DOT 5.1 Brake Fluid
| DOT 5.1 Brake Fluid [message #352165] |
Thu, 13 February 2020 13:55  |
rjw
Messages: 697
Registered: September 2005
Karma: 4
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A couple of years ago, I was en-route in our GMC from Reno, NV (attended a wedding there) back home to Troy, MI via Albuquerque, NM. To add fun and excitement to the return trip I decided it would be fun to drive through Death Valley as I had never been there. It was April after all and the young lady at the visitor's center near Lone Pine, California suggested that the drive in a RV would be no trouble in April as trucks do it all the time.
Well the trip down into the valley was way more fun and excitement than I had anticipated. SHE wants no part of that kind of fun in any future trips.
Upon leveling off near sea level the Tire Pressure Monitoring system stated to beep indicating an overheat on the front 2 tires. At the same time I started to lose quite a bit of braking. Good thing we were level and we had a place to pull over and stop. I got out and found that the newly installed 80MM calipers were hot enough to smoke. So I figured the DOT 3 brake fluid had been at or near the fluid's boiling point. After I let things cool, we had normal braking. The rest of the drive through the valley was no problem with brakes but I did have issues with fuel vapor and ignition that I could describe in a later post. But we did make it back home OK.
During a visit to Dave Lenzi last week to pick up some more parts (his basement is like Disney Land), we discussed my lack of brakes on that trip. He suggested among other things that I might want to consider DOT 5.1 fluid as it has much higher boiling temperatures than the DOT 3 I had in my system and was compatible with both DOT 3 and DOT 4 unlike DOT 5.
I am wondering if anyone has an opinion on going to DOT 5.1
Thanks
Richard
76 Palm Beach
SE Michigan
www.PalmBeachGMC.com
Roller Cam 455, TBI+EBL, 3.42 FD, 4 Bag, Macerator, Lenzi (brakes, vacuum system, front end stuff), Manny Tranny, vacuum step, Tankless + OEM water heaters.
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| Re: DOT 5.1 Brake Fluid [message #352167 is a reply to message #352165] |
Thu, 13 February 2020 15:17  |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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1) if you are boiling DOT 3 you have bad driving habits. You will also cook the grease and glaze linings.
2) silicone based fluids love to leak past seals in my experience.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: DOT 5.1 Brake Fluid [message #352168 is a reply to message #352165] |
Thu, 13 February 2020 15:37 |
kingd
Messages: 592
Registered: June 2004
Karma: 2
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Senior Member |
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Remeber, 5.1 is absolutely compatible with DOT 3
For some reason. "they" decided to make the latest version
Of conventional brake fluid 5.1
DAVE KING
lurker, wannabe
Toronto, Ontario, Canada
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| Re: [GMCnet] DOT 5.1 Brake Fluid [message #352169 is a reply to message #352166] |
Thu, 13 February 2020 15:51 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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GM recommends D.O.T. 3. What you experienced in Death Valley was what we
call Extreme Service. IF your brake fluid was fresh and contained
absolutely NO WATER OR OTHER CONTAMINANTS, when things cooled down, you
should have been fine to continue to use your coach normally. Proceed
downgrade in the same gear that you would climb it. Use the brakes
intermittently, and give them time to dissipate heat between
applications. If you "ride the pedal" continously on downgrades, be
prepared to glaze the drums and rotors unless you use aggressive type
linings like ceramic or semi- metallic or full metallic ones. 12,000 pound
vehicles require driving like a truck. Lots of following distance. Frequent
rest breaks are a really good idea, as well.
Jim Hupy
Salem, Oregon
On Thu, Feb 13, 2020, 1:15 PM Johnny Bridges via Gmclist <
gmclist@list.gmcnet.org> wrote:
> How clean of type 3 does the system have to be to put 5.1 in? Is it (5.1)
> compatible with the o - rings and seals in the coach? It seems the time to
> use it would be when you replace the cylinders and calipers... you'd have
> to remove them to get all the existing fluid out anyway, or turn the coach
> upside down to drain them :)
>
> --johnny
> --
> Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
> Braselton, Ga.
> I forgive them all, save those who hurt the dogs. They must answer to me
> in hell
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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| Re: DOT 5.1 Brake Fluid [message #352171 is a reply to message #352165] |
Thu, 13 February 2020 16:01 |
Scott Nutter
Messages: 782
Registered: January 2015
Location: Houston/San Diego
Karma: 4
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Emery had a good post about the 5.1 brake fluid about a year ago. I believe he went with the Wagner brand. There was a lot of good info in the posts.
Scott.
Scott Nutter
1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI
Houston, Texas
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| Re: DOT 5.1 Brake Fluid [message #352172 is a reply to message #352167] |
Thu, 13 February 2020 16:33 |
rjw
Messages: 697
Registered: September 2005
Karma: 4
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Senior Member |
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JohnL455 wrote on Thu, 13 February 2020 16:171) if you are boiling DOT 3 you have bad driving habits. You will also cook the grease and glaze linings.
2) silicone based fluids love to leak past seals in my experience.
Have you ever driven down to Death Valley from California in a GMC? I think I have good driving habits thank you. I don't ride the brakes and try to give them time to cool between brake applications.
Richard
76 Palm Beach
SE Michigan
www.PalmBeachGMC.com
Roller Cam 455, TBI+EBL, 3.42 FD, 4 Bag, Macerator, Lenzi (brakes, vacuum system, front end stuff), Manny Tranny, vacuum step, Tankless + OEM water heaters.
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| Re: [GMCnet] DOT 5.1 Brake Fluid [message #352173 is a reply to message #352171] |
Thu, 13 February 2020 16:26 |
sgltrac
Messages: 2797
Registered: April 2011
Karma: 1
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5.1 is compatible with dot 3. That means you can have some dot 3 left in
your system with no issues (other than the 3 portion may boil). I switched
my front brake system on my off road bike to 5.1 and that resolved all of
the brake fade conditions I encountered prior.
Sully
Bellevue wa
On Thu, Feb 13, 2020 at 2:01 PM Scott Nutter via Gmclist <
gmclist@list.gmcnet.org> wrote:
> Emery had a good post about the 5.1 brake fluid about a year ago. I
> believe he went with the Wagner brand. There was a lot of good info in the
> posts.
> Scott.
> --
> Scott Nutter
> 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final
> drive, Quad bags, tankless water heater, everything Lenzi. Alex Ferrera
> installed MSD Atomic EFI
> Houston, Texas
>
> _______________________________________________
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> Unsubscribe or Change List Options:
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Sully
77 Royale basket case.
Future motorhome land speed record holder(bucket list)
Seattle, Wa.
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| Re: [GMCnet] DOT 5.1 Brake Fluid [message #352174 is a reply to message #352172] |
Thu, 13 February 2020 17:00 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Yes, I have driven that exact road. In my GMC. Pulling a trailer. And I
never overheated my brakes. And I have a 1978 Royale. A heavy coach. But, I
have a couple of upgrades that perhaps you do not. 80 MM front Calipers
with Sticky Ceramic lining, and I have different diameter wheel hydraulic
cylinders, which prevents rear wheel lockup. And I use semi-metalic premium
riveted linings. They are noisy, and grabby when they haven't been used
for a while, but they stop the coach very well.
That is about the best that stock brakes can be without reaction arms
and 6 wheel disc brakes. That drop into death Valley is a fair test on
whether your brakes need attention. But, there are much worse hills than
that.
One that comes to mind is is British Columbia, Canada. Near Whistler
Ski resort. 23 miles of continuous downhill and an 18% grade. I did not
stutter. 18%. The most severe test I personally have encountered. We
traveled that one as a group. At least 7 GMCs. Some towing, some not.
Every coaches brakes were smoking, including mine. A butt-puckering
adventure for sure. These coaches were state of the art, 40 years ago. Not
by today's standards.
Jim Hupy
Salem, Oregon
On Thu, Feb 13, 2020, 2:33 PM RJW via Gmclist
wrote:
> JohnL455 wrote on Thu, 13 February 2020 16:17
>> 1) if you are boiling DOT 3 you have bad driving habits. You will also
> cook the grease and glaze linings.
>>
>> 2) silicone based fluids love to leak past seals in my experience.
>
> Have you ever driven down to Death Valley from California in a GMC? I
> think I have good driving habits thank you. I don't ride the brakes and try
> to
> give them time to cool between brake applications.
> --
> Richard
> 76 Palm Beach
> SE Michigan
> www.PalmBeachGMC.com
>
>
> Coop Roller Cam 455, Howell TBI + EBL, 3.42 FD, Quadra Bag, Macerator,
> Lenzi stuff, Manny Tranny etc.
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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| Re: [GMCnet] DOT 5.1 Brake Fluid [message #352175 is a reply to message #352174] |
Thu, 13 February 2020 17:52 |
rjw
Messages: 697
Registered: September 2005
Karma: 4
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Senior Member |
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James Hupy wrote on Thu, 13 February 2020 18:00Yes, I have driven that exact road. In my GMC. Pulling a trailer. And I
never overheated my brakes. And I have a 1978 Royale. A heavy coach. But, I
have a couple of upgrades that perhaps you do not. 80 MM front Calipers
with Sticky Ceramic lining, and I have different diameter wheel hydraulic
cylinders, which prevents rear wheel lockup. And I use semi-metalic premium
riveted linings. They are noisy, and grabby when they haven't been used
for a while, but they stop the coach very well.
That is about the best that stock brakes can be without reaction arms
and 6 wheel disc brakes. That drop into death Valley is a fair test on
whether your brakes need attention. But, there are much worse hills than
that.
Jim Hupy
Salem, Oregon
That trip down to Death Valley was a wake up call that my brakes needed attention. It is apparent that 80MM calipers with stock drum (probably not optimally adjusted) brakes in an over weight vehicle is not enough for dealing with the significant downhill grades often seen in the western US. That is the main reason that I had a visit to see Dave Lenzi who knows more about brakes than I do.
My question was not about how bad my brakes are, or to be ridiculed about my ability to drive a GMC in the mountains.
I was asking about about DOT 5.1 to help me make an informed decision on whether to I switch to that during my brake system rebuild.
Richard
76 Palm Beach
SE Michigan
www.PalmBeachGMC.com
Roller Cam 455, TBI+EBL, 3.42 FD, 4 Bag, Macerator, Lenzi (brakes, vacuum system, front end stuff), Manny Tranny, vacuum step, Tankless + OEM water heaters.
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| Re: [GMCnet] DOT 5.1 Brake Fluid [message #352176 is a reply to message #352165] |
Thu, 13 February 2020 17:42 |
Emery Stora
Messages: 959
Registered: January 2011
Karma: 4
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Senior Member |
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> On Feb 13, 2020, at 12:55 PM, RJW via Gmclist wrote:
>
> A couple of years ago, I was en-route in our GMC from Reno, NV (attended a wedding there) back home to Troy, MI via Albuquerque, NM. To add fun and
> excitement to the return trip I decided it would be fun to drive through Death Valley as I had never been there. It was April after all and the young
> lady at the visitor's center near Lone Pine, California suggested that the drive in a RV would be no trouble in April as trucks do it all the time.
>
> Well the trip down into the valley was way more fun and excitement than I had anticipated. SHE wants no part of that kind of fun in any future trips.
>
>
> Upon leveling off near sea level the Tire Pressure Monitoring system stated to beep indicating an overheat on the front 2 tires. At the same time I
> started to lose quite a bit of braking. Good thing we were level and we had a place to pull over and stop. I got out and found that the newly
> installed 80MM calipers were hot enough to smoke. So I figured the DOT 3 brake fluid had been at or near the fluid's boiling point. After I let
> things cool, we had normal braking. The rest of the drive through the valley was no problem with brakes but I did have issues with fuel vapor and
> ignition that I could describe in a later post. But we did make it back home OK.
>
> During a visit to Dave Lenzi last week to pick up some more parts (his basement is like Disney Land), we discussed my lack of brakes on that trip. He
> suggested among other things that I might want to consider DOT 5.1 fluid as it has much higher boiling temperatures than the DOT 3 I had in my system
> and was compatible with both DOT 3 and DOT 4 unlike DOT 5.
>
> I am wondering if anyone has an opinion on going to DOT 5.1
>
> Thanks
>
>
> --
> Richard
> 76 Palm Beach
> SE Michigan
> www.PalmBeachGMC.com
>
>
> Coop Roller Cam 455, Howell TBI + EBL, 3.42 FD, Quadra Bag, Macerator, Lenzi stuff, Manny Tranny etc.
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
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| Re: [GMCnet] DOT 5.1 Brake Fluid [message #352178 is a reply to message #352169] |
Thu, 13 February 2020 17:57 |
Emery Stora
Messages: 959
Registered: January 2011
Karma: 4
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Senior Member |
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Yes, GM recommended Dot 3 but only because Dot 5.1 did not exist at the time.
Brake fluids change for the better from time to time as labs develop fluids with better characteristics, just as Oils and Transmission fluids have changed.
I highly recommend change your GMC over to DOT 5.1.
Emery Stora
77 Kingsley
Frederick, CO
> On Feb 13, 2020, at 2:51 PM, James Hupy via Gmclist wrote:
>
> GM recommends D.O.T. 3. What you experienced in Death Valley was what we
> call Extreme Service. IF your brake fluid was fresh and contained
> absolutely NO WATER OR OTHER CONTAMINANTS, when things cooled down, you
> should have been fine to continue to use your coach normally. Proceed
> downgrade in the same gear that you would climb it. Use the brakes
> intermittently, and give them time to dissipate heat between
> applications. If you "ride the pedal" continously on downgrades, be
> prepared to glaze the drums and rotors unless you use aggressive type
> linings like ceramic or semi- metallic or full metallic ones. 12,000 pound
> vehicles require driving like a truck. Lots of following distance. Frequent
> rest breaks are a really good idea, as well.
> Jim Hupy
> Salem, Oregon
>
> On Thu, Feb 13, 2020, 1:15 PM Johnny Bridges via Gmclist gmclist@list.gmcnet.org> wrote:
>
>> How clean of type 3 does the system have to be to put 5.1 in? Is it (5.1)
>> compatible with the o - rings and seals in the coach? It seems the time to
>> use it would be when you replace the cylinders and calipers... you'd have
>> to remove them to get all the existing fluid out anyway, or turn the coach
>> upside down to drain them :)
>>
>> --johnny
>> --
>> Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
>> Braselton, Ga.
>> I forgive them all, save those who hurt the dogs. They must answer to me
>> in hell
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
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| Re: DOT 5.1 Brake Fluid [message #352179 is a reply to message #352166] |
Thu, 13 February 2020 18:12 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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Look at this chart and decide what you want to use. I have used DOT 4 in everything from my motorcycles to every on road vehicle own or work on. I have never tried DOT 5.1 . The numbers in this chart are the minimum boiling points required to meet the DOT standard.
Dry boiling point is what you get out of the can.
Wet boiling point is what you get after the fluid is installed for a couple of years and has absorbed some moisture out of the air.
I suggest that you want the best (highest) wet boiling point that you can find.
I have a cheapy tester (under $10.00) that you can stick in your reservoir and measure the amount of that you fluid has absorbed.
https://epicbleedsolutions.com/blogs/faq/whats-the-difference-between-dot-4-and-dot-5-1-brake-fluid#
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] DOT 5.1 Brake Fluid [message #352181 is a reply to message #352179] |
Thu, 13 February 2020 18:58 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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I am sorry and apologize to you if you feel insulted by my comments about
"riding the brakes, etc. I assure you that my intention was not to insult
or demean you in any way. We encounter many people here on the net. Some
are novices, with absolutely no experience driving heavy vehicles down
steep grades, and some are more knowledgeable than that. I have no way to
determine which category every person fits into, so I rely upon giving too
much information just to make sure I cover all the bases. Again, sorry if I
hurt your feelings.
Jim Hupy
Salem, Oregon
On Thu, Feb 13, 2020, 4:13 PM Ken Burton via Gmclist <
gmclist@list.gmcnet.org> wrote:
> Look at this chart and decide what you want to use. I have used DOT 4 in
> everything from my motorcycles to every on road vehicle own or work on. I
> have never tried DOT 5.1 . The numbers in this chart are the minimum
> boiling points required to meet the DOT standard.
>
> Dry boiling point is what you get out of the can.
>
> Wet boiling point is what you get after the fluid is installed for a
> couple of years and has absorbed some moisture out of the air.
>
> I suggest that you want the best (highest) wet boiling point that you can
> find.
>
> I have a cheapy tester (under $10.00) that you can stick in your reservoir
> and measure the amount of that you fluid has absorbed.
>
>
> https://epicbleedsolutions.com/blogs/faq/whats-the-difference-between-dot-4-and-dot-5-1-brake-fluid#
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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| Re: DOT 5.1 Brake Fluid [message #352189 is a reply to message #352165] |
Fri, 14 February 2020 07:58 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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Senior Member |
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The two grades that amount to anything around here that I regularly pull are MontEagle and Culowee Mountain, depending where I'm going. Every bit as steep as the western ones, but not nearly as long. I hang the coach in second and coast down without brakes until it hits 60 per, then quickly pull it down to 45 and proceed. This give them plenty of time to cool. When I replaced the shoes in back, they were cooked. In that the PO hauled a heavy trailer across the norther California mountains, not surprising.
Thanks for the input on 5.1, I'll consider it when the test shows the now new 3 fluid has picked up some moisture. If sonmeone said, I missed it, but it sounds as if the 5.1 would be as hygroscopic as the 3.
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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| Re: DOT 5.1 Brake Fluid [message #352190 is a reply to message #352165] |
Fri, 14 February 2020 08:59 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Senior Member |
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Emery my reply 2) was poorly worded. It sounded like I was saying 5.1 was silicone based. But still true that silicone loves to leak in DOT 3 equipment. I have a friends coach stored here with that very issue. Leaked all of the aft chamber out MC seal. Too bad we don't have more gears. The RPM changes from gear to gear are too large going up and down grades over 6%. Some of these grades may just require 1st gear at a low speed where 2nd would become a run away.
John Lebetski
Woodstock, IL
77 Eleganza II
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