RockAuto now offers Monroe's new line of Magnum Strut / Coil Spring / Mount Assemblies, which are specifically designed for upgrading 1/2 Ton trucks to improve handling while towing, hauling and plowing. Monroe Magnum Strut / Coil Spring / Mount Assemblies feature a variable rate coil spring for increased support under load and Monroe's patented Acceleration Sensitive Damping (ASD) technology provides greater control for handling while improving ride comfort. Whether you are still plowing snow or ready to tow the boat to the lake, Monroe Magnum Strut / Coil Spring / Mount Assemblies can help make the drive safer and more pleasant.

RockAuto offers a selection of OE replacement Strut / Coil Spring / Mount Assemblies for most popular cars and trucks, including Monroe Quick-Strut, KYB Strut Plus, Gabriel ReadyMount, Ultra-Power and many more! Strut / Coil Spring / Mount Assemblies save on installation time and avoid surprises by offering a complete bolt-on solution that fully restores OE ride/handling and does not require a spring compressor. Strut / Coil Spring / Mount Assemblies for your specific vehicle can be found under the “Suspension” category in the RockAuto.com catalog. Get up to $100 cash back on Shocks and Struts by Monroe (through March 31, 2019) and KYB (through April 30, 2019).

More Rebates
Go to the Promotions & Rebates page to see details for the Monroe and KYB rebates and additional rebates for Spark Plugs, Tachometers, Exhaust Systems, Clutch System Kits, Brake Kits, Divetrain Parts, Bearings, Hubs and Water Pumps and more being offered by ACDelco, AMS Automotive, AutoMeter, Autolite, DynoMax, Power Stop, USA Standard Gear and WJB.

While shopping, watch for the yellow "Promotion/Rebate" star next to the part names to help you save even more.

Stovebolt.com is a comprehensive online source for sharing knowledge of pre-1973 Chevrolet and GMC trucks. The forums are for discussions directly related to the care, restoration and use of antique GM trucks. If you are restoring, preserving or just driving an ole "Stovebolt," this website has information you will find useful for living with your old truck. You will find members who share information on everything from 1/2-tons to 3-tons, COEs, Panels and 'Burbs, Fire Trucks, Tow Trucks -- lots of trucks in all shapes, sizes and stages of restoration.

If you are the administrator or member of a forum and you would like to see your website featured in an upcoming newsletter and receive a discount code to share with your members, contact marketing@rockauto.com.

Many years ago, I worked in a two bay "service station" on the graveyard shift. My duties were primarily clean-up and full service gas pump attendant. We did not stock parts outside of a few belts, hoses, batteries and tires; it is the middle of the night after all. Gas, oil and clean windshields was the name of the game.

One evening, a fellow pulls in, rear brakes grinding loudly and smoking hot; literally smoking and light your cigarette hot! He is in a panic, he has places to go and people to see and this is an (his) emergency. I tried to explain that a) I have no parts and b) it was going to be some time before those brake drums were cool enough to touch.

He was not understanding any of this and wanted his car in the bay and on the rack and now! It was getting a little unnerving as I continued to tell him "no parts and too hot," and things were escalating when I noted a quick fix! I reached in and pulled the brake release, the emergency brake pedal popped back up. He said nothing; his look said enough. He drove away. I went back to cleaning the bays.

Joel in Missouri

Tell us about your most infamous auto repair blunder or unconventional fix. Use your woe to help others avoid similar mistakes or share off-the-wall solutions that worked (at least for a while!). Please email your story to flamur@rockauto.com. Include your mailing address and if you would like a RockAuto T-Shirt (please let us know your shirt size) or Hat if we publish your story. See the T-Shirts and Hats under Tools & Universal Parts in the catalog. The story will be credited using only your first name and your vague geographic location (state, province, country, continent, etc.) so you can remain semi-anonymous!

Why does the 250cid (4.1L) six cylinder in the 1968 Pontiac Firebird not have a timing chain?

A. This L-head engine, in use at GM since 1959, has the valves in the cylinder block rather than the head. The crankshaft and camshaft are close together allowing direct-drive gears to link the two shafts.

B. It is the same flat-six engine used in the Chevrolet Corvair. This and other horizontal piston engines (Subaru, Porsche, etc.) use gears to connect the camshaft in the bottom of the engine to the crankshaft above.

C. John DeLorean oversaw the design of this state-of-the-art overhead cam engine. The OE fiberglass reinforced rubber timing belt allowed the engine to reach higher revs for more power.

Answer below

The driver behind the wheel of the 2004 Ford Mustang GT straining to go at the stoplight has no idea that the 2016 Chevy Express 4500 airport shuttle van sitting next to him has hydroboost (hydro-boost) under the hood. The light turns green and the Mustang roars off, leaving the lumbering airport shuttle van far behind. Unbeknownst to its driver, the Mustang has hydroboost under its hood too!

Hydroboost is the awesome sounding name for a power brake booster driven by the power steering pump rather than vacuum. A hydroboost power brake booster takes the place of the more familiar large vacuum diaphragm sandwiched between the brake master cylinder and the firewall. Trucks often have hydroboost systems because their diesel engines do not produce vacuum (unless they have vacuum pumps) or because the throttles on their hard working gasoline engines are wide open for long periods of time, limiting the amount of vacuum available to a vacuum operated power brake booster.

Hydroboost (top) & Vacuum Power Brake Boosters

Cars and vans with small engine compartments may also take advantage of the compactness of hydroboost power brake boosters. Sometimes the largest displacement engine options come with hydroboost and smaller engines have vacuum power brake boosters. Vans with dual rear wheels may get hydroboost while vans with single rear wheels come with vacuum brake boosters. Look under "Brake & Wheel Hub" in the RockAuto.com catalog to see what Power Brake Boosters your vehicle came equipped with. Also take a look under the hood to verify that your brake master cylinder is mounted to a large round vacuum diaphragm housing or a compact hydroboost unit.

A failing hydroboost power brake booster may leak power steering fluid, make continuous noise and/or fail to provide brake assist. (Pump the brake pedal with the engine off. Once the engine is started, the brake pedal should sink slightly and then push back against your foot as the power steering system is pressurized.)

Hydroboost may assist the brakes, but it is part of the hydraulic power steering system. A loose, worn or missing power steering pump belt will effect both the steering and brakes. Debris from power steering hoses that are crumbling internally can clog/damage both the power steering pump and the hydroboost power brake booster. Hydroboost systems may use a different power steering pump than engines equipped with vacuum brake systems, so take a close look at the photos and descriptions when selecting a new power steering pump (found under "Steering").

When a hydroboost unit is replaced, air needs to be bled out of the power steering fluid following the instructions that came with the new hydroboost power brake booster and/or the vehicle's repair manual (found under "Literature" in the RockAuto.com catalog). Be sure to keep brake fluid separate from power steering fluid. Using the wrong fluids will destroy seals in both the power steering and brake systems.

Maybe RockAuto should make some "HydroBoost" decals so Astro, F-250, Hummer, etc. owners can tell the world their vehicles have something special assisting the brakes!

Tom Taylor,
RockAuto.com

To read more of Tom's articles, click this link and choose from story titles on the Newsletter Archives page.

Share Your Hard Work
Do you purchase parts from RockAuto? If so, RockAuto would like to give you the opportunity to have your car or truck possibly featured in one (or occasionally more) of our publications such as the monthly newsletter, collector magnets, RockAuto social media or other commercial use. New, old, import, domestic, daily driver, trailer queen, classic, antique, we want to see them all! Please email flamur@RockAuto.com with your vehicle's history, interesting details, your favorite images (tips for taking pictures of your car) and what parts from RockAuto you have used.

Why does the 250cid (4.1L) six cylinder in the 1968 Pontiac Firebird not have a timing chain?

A. This L-head engine, in use at GM since 1959, has the valves in the cylinder block rather than the head. The crankshaft and camshaft are close together allowing direct-drive gears to link the two shafts.

B. It is the same flat-six engine used in the Chevrolet Corvair. This and other horizontal piston engines (Subaru, Porsche, etc.) use gears to connect the camshaft in the bottom of the engine to the crankshaft above.

Answer: C. John DeLorean oversaw the design of this state-of-the-art overhead cam engine. The OE fiberglass reinforced rubber timing belt allowed the engine to reach higher revs for more power.

Back up to trivia question