The result of the wrong fluid

[Johan Bornman]

A customer came in with sticky brake levers this week and couldn't understand why the levers would not budge, especially after he went and bought a litre of Shimano Mineral Oil from CRC and bled his Hope brakes with it.

 

It was quite interesting fixing that little mistake - Hope brakes work with brake fluid (DOT fluid if you like) and Shimano with oil. He injected oil into his brakes and within hours the levers were seized.

 

The one lever still kinda worked, but was stiff. The next day when I had to disassemble it, I could not get the master cyclinder piston out. I had to punch it out with a pin punch. I then noticed how much the rubbers have swollen from exposure to incompatible oil. So much so that the two piston seals were locking the piston solidly in place. When I say solid, that's what I mean, hammer blows were required to free it.

 

It was a real pain stripping and cleaning everyrhing. Even the hoses had to be flushed out, washed and dried. Please don't do this at home.

 

Here's a photo of the reservoir cap seal. The one on the left is the new one, the one on the right the swollen one.

 

Edited December 9, 2012 by Johan Bornman

[DIPSLICK]

We work on brakes for cars trucks and heavy earth machinery, I once had a customer screaming and shouting at me about a seal failure saying the seal quality was poor, when I explained that it was contamination he still would not listen, so I opened two new kits but the one into brake fluid and the other into mineral oil when the kit started swelling in two min the look on his face was priceless . As the saying goes RTFI

[Johan Bornman]

We work on brakes for cars trucks and heavy earth machinery, I once had a customer screaming and shouting at me about a seal failure saying the seal quality was poor, when I explained that it was contamination he still would not listen, so I opened two new kits but the one into brake fluid and the other into mineral oil when the kit started swelling in two min the look on his face was priceless . As the saying goes RTFI

 

It's weird that truck owners should even think of mineral oil in their brake reservoirs. At least with cyclists there is some confusion, with two systems and all that. But gooing oil into your truck brake reservoir is just super daft.

[DIPSLICK]

 

 

It's weird that truck owners should even think of mineral oil in their brake reservoirs. At least with cyclists there is some confusion, with two systems and all that. But gooing oil into your truck brake reservoir is just super daft.

Actually most new merc actors , man trucks ( on there clutch hyd, masters and servos ) and lots of off road application is mineral oil,like bell tippers, terex the stuff running on the mines

[Mackie]

I have missed your workshop tales JB.

[koukie]

But why does this happen. I would rather think that DOT fluid will damage a rubber seal than mineral oil.

Edited December 9, 2012 by koukie

[Helpmytrap]

But why does this happen. I would rather think that DOT fluid will damage a rubber seal than mineral oil.

I don't think damage is the right word. It's just a property of that certain rubber which allows it to absorb the mineral oil making it swell up. Dumb example but put oil on wood and it will be absorbed but put oil on sealed/varnished wood and watch nothing happen.

[pastapouch]

We have an Afrikaans saying... elke vlieg op sy dr0l. that means, do what you can, leave the rest to the people who knows how to do it.

[koukie]

This talking about oil get me worried now, Johan i have a whole bottle of fork oil 5w, boutht it a motorcycle shop but I want to use it on my chain aswell since its a nice thin oil, will that be fine, cant see how it will not be fine but just making sure.

Edited December 9, 2012 by koukie

[Johan Bornman]

This talking about oil get me worried now, Johan i have a whole bottle of fork oil 5w, boutht it a motorcycle shop but I want to use it on my chain aswell since its a nice thin oil, will that be fine, cant see how it will not be fine but just making sure.

 

It will do no damage whatsoever to your chain, other metal parts, paint or wherever else it may fall.

 

However, it is the wrong oil for the job. Swap it with someone for a can of engine oil. Then you'l be better off. If you put that stuff on your chain then you'll end up with oil wheels. It is so think it will splatter everywhere.

[Johan Bornman]

Actually most new merc actors , man trucks ( on there clutch hyd, masters and servos ) and lots of off road application is mineral oil,like bell tippers, terex the stuff running on the mines

 

I didn't know that. Thanks

[DIPSLICK]

As Johan says it will do nothing to your chain, but stick to the right lubes, oils viscosity works in funny ways, sounds simple but you can phone 5 different agents, say Nissan,

Toyota, BMW , Honda,Volkswagen they would all give you different gearbox oils for there different gearboxes, but if you walk into a spares shop they will give you 20w/50

And say that's all you need, but you can actually seize your box, going back to the why it damages the seals, it's a simple matter of different types of rubbers for different applications and if you use the wrong rubber with the wrong oil/ fluid the seal has a chemical reaction and breaks down

[Cassie]

We have an Afrikaans saying... elke vlieg op sy dr0l. that means, do what you can, leave the rest to the people who knows how to do it.

 

Guys. its really not rocket science...Step (1) FIND OUT which oil your sytem require... rest is plain simple!!

[Cassie]

A customer came in with sticky brake levers this week and couldn't understand why the levers would not budge, especially after he went and bought a litre of Shimano Mineral Oil from CRC and bled his Hope brakes with it.

 

It was quite interesting fixing that little mistake - Hope brakes work with brake fluid (DOT fluid if you like) and Shimano with oil. He injected oil into his brakes and within hours the levers were seized.

 

The one lever still kinda worked, but was stiff. The next day when I had to disassemble it, I could not get the master cyclinder piston out. I had to punch it out with a pin punch. I then noticed how much the rubbers have swollen from exposure to incompatible oil. So much so that the two piston seals were locking the piston solidly in place. When I say solid, that's what I mean, hammer blows were required to free it.

 

It was a real pain stripping and cleaning everyrhing. Even the hoses had to be flushed out, washed and dried. Please don't do this at home.

 

Here's a photo of the reservoir cap seal. The one on the left is the new one, the one on the right the swollen one.

 

A customer came in with sticky brake levers this week and couldn't understand why the levers would not budge, especially after he went and bought a litre of Shimano Mineral Oil from CRC and bled his Hope brakes with it.

 

It was quite interesting fixing that little mistake - Hope brakes work with brake fluid (DOT fluid if you like) and Shimano with oil. He injected oil into his brakes and within hours the levers were seized.

 

The one lever still kinda worked, but was stiff. The next day when I had to disassemble it, I could not get the master cyclinder piston out. I had to punch it out with a pin punch. I then noticed how much the rubbers have swollen from exposure to incompatible oil. So much so that the two piston seals were locking the piston solidly in place. When I say solid, that's what I mean, hammer blows were required to free it.

 

It was a real pain stripping and cleaning everyrhing. Even the hoses had to be flushed out, washed and dried. Please don't do this at home.

 

Here's a photo of the reservoir cap seal. The one on the left is the new one, the one on the right the swollen one.

 

 

Hey Johan... Tell you client to make some smaller quantities (200ml batches) of that 1L Mineral oil available heer on the HUB...

He can at least offset some of the costs that he incured???

 

Great post by the way!!

[TiBones]

Hey JB, Thanks for seals and oil(s) on Fri for my fork. Job went off perfectly except I destroyed my star nut in the process....

[nishiki]

Amazes me how people refuse to read the manual. A simple google and you can easily find which oil to use with Hope. This laziness came at a price though...1 liter of mineral oil ( who buys a liter of this stuff haha!!!) and a whole overhaul. I'd live to see what this person does to 'repair' his home. I can guess a lot of sticky tape and presstic all over the show