- Car Care & Maintenance
Auto shop equipment machine On-car brake lathes.
The on-car brake lathe.
Using an on car brake lathe takes a skilled operator who understands the value of his or her experience with setting the brake lathe up carefully.
Choosing which type of on-car brake lathe to buy has a lot to do with your suspension and brake knowledge and experience with the market you are serving, so there are a few things to consider.
If you have a small auto repair shop that does general servicing and repairs, an on-car brake lathe can be quite useful to your bottom line and more importantly provide your customer with the satisfaction that they have chosen a workshop that can handle all their needs in one place.
Being portable and small, and requiring only household voltage, it can be set up and used quickly to do a small job such as cleaning the discs up after an overenthusiastic or emergency stop that has left the disc rotor burnt or warped slightly. They are also handy to quickly unglaze a rotor. Where they are useless is when you have a slightly worn wheel bearing that moves under load thus distorting the cut.
A bench mounted brake lathe always machines true to it's own surface because the cars other components are not involved in the configuration.
Simple on car brake lathe.
Hennessy on car brake lathe
The small on-car brake lathe pictured on the right was probably the best of the early models, but you did need a few different mount fittings to attach to the caliper mount on the hub. These are very handy little brake lathes that can do a perfect job if mounted correctly and spun evenly at the correct speed. If you have good fabrication skills you can make your own mounting attachment and fit most vehicles. Set up is best achieved with a fine dial gauge to check alignment.
Most suited to the workshop that has a good technician/motor engineer who can understand it's limitations and fabricate new attachments that can no longer be purchased Some of these brake lathes are very simple and cheap and usually require the car's motor to drive the wheels while the disc cutters machine the disc
The later model on-car brake lathes have remained much as they have been for 30 years, except for much needed changes in the control box and switching which were prone to get broken on early models of all makes I know of.
Later ones are more complex having an adapter
that fits on the wheel hub where the wheel is usually bolted to drive
the wheel while the disc is being cut.
The cutter head and adjustments are as good as the larger machines, but you can't just take deep cuts like you could on an Ammco or FMC bench mounted machine. If you try to cut too deep the rotor will chatter the cutters leaving an uneven cut.
Early VGB 620 On Car Brake Lathe
The later model on-car brake lathes have remained much as they have been for 30 years, except for much needed changes in the control box and switching gear on Australian models that run 240vac that had capacitors that were large and expensive to replace and were also prone to get broken because of there location on the outside of the lathe.
These later brake lathes are more complex having a large heavy motor driving an adapter that fits on the wheel hub where the wheel is usually bolted to drive the wheel while the disc is being cut, they needed a stand. These early stands left a lot to be desired and you needed to use a fare bit of strength to man-hand the unit in to the stand and set it up to hub height..
Later VBG On Car brake lathe
This later series of the VBG have a counter balanced stand that was much easier to manuever and held more adapters. This is still a sought after item for those who know brake lathes as it is a good quality machine that will do a stack of work.
There are plenty of good on-car brake lathes on the market, as many workshops bought them and never learnt how to use them. Many I have purchased were as new.
If you buy a used one, make sure of it's condition, that it has all it's hub adaptors, (expensive as hell to replace.) and that ALL the stand is complete. These later stands consist of many small parts that get lost.
This is a cheap way to get an on-car brake lathe, and if you make sure you get a good one that is complete, it will pay for itself quickly and give you many years of trouble free operation afterwards.
When to use an on-car brake lathe.
An on car brake lathe is very handy for some brake jobs where the rotor is difficult to remove because of the vehicle suspension design. It also saves all the time needed to disassemble then reassemble the brakes.
Many auto repair shop that I supplied did wheel services and minor or major suspension repairs. If this is the case with your repair shop, an on-car unit will give you another source of profit.
With an on-car brake lathe you can machine the discs on the car and provide your customers with a faster disc rotor machining service than your competitors who have just a Bench mounted brake lathe. Also the car remains intact and you do not have to wait for the finished discs to be returned or even have to go pick them up. Another good reason to own a brake lathe yourself.
This is the Pro-cut on-car brake lathe with a computer controlled guide for the cutter head. These are very good, but like the other early models you still need a good operator. The biggest worry with the late model ones is dropping them. I have repaired quite a few with broken electronics
A good used earlier model will do the same job in the hands of a good technician, perhaps with one exception.
The main advantage of the computer guided cut is that it will work better on disc rotors with less than great metallurgy. In other words, they don't dig channels in the soft metal spots in a cheap disc rotor.